1661635480 has 16 divisors (see below), whose sum is σ = 3738679920. Its totient is φ = 664654176.

The previous prime is 1661635463. The next prime is 1661635487. The reversal of 1661635480 is 845361661.

It is a super-2 number, since 2×1661635480² = 5522064936789660800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 41540887 = 1661635480 / (1 + 6 + 6 + 1 + 6 + 3 + 5 + 4 + 8 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661635487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20770404 + ... + 20770483.

It is an arithmetic number, because the mean of its divisors is an integer number (233667495).

Almost surely, 2^1661635480 is an apocalyptic number.

1661635480 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661635480 is an abundant number, since it is smaller than the sum of its proper divisors (2077044440).

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

1661635480 is a wasteful number, since it uses less digits than its factorization.

1661635480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41540898 (or 41540894 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 1661635480 is about 40763.1632727393. The cubic root of 1661635480 is about 1184.4368727339.

The spelling of 1661635480 in words is "one billion, six hundred sixty-one million, six hundred thirty-five thousand, four hundred eighty".