1661635040 has 192 divisors, whose sum is σ = 4426228800. Its totient is φ = 588736512.

The previous prime is 1661635021. The next prime is 1661635049. The reversal of 1661635040 is 405361661.

It is a super-2 number, since 2×1661635040² = 5522062012311603200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 1661634988 and 1661635006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661635049) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10193999 + ... + 10194161.

It is an arithmetic number, because the mean of its divisors is an integer number (23053275).

Almost surely, 2^1661635040 is an apocalyptic number.

1661635040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661635040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2213114400).

1661635040 is an abundant number, since it is smaller than the sum of its proper divisors (2764593760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661635040 is a wasteful number, since it uses less digits than its factorization.

1661635040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246 (or 212 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 1661635040 is about 40763.1578757093. The cubic root of 1661635040 is about 1184.4367681879.

The spelling of 1661635040 in words is "one billion, six hundred sixty-one million, six hundred thirty-five thousand, forty".