1662643840 has 256 divisors, whose sum is σ = 4805619840. Its totient is φ = 541900800.

The previous prime is 1662643837. The next prime is 1662643859. The reversal of 1662643840 is 483462661.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1662643793 and 1662643802.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3385995 + ... + 3386485.

Almost surely, 2^1662643840 is an apocalyptic number.

1662643840 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 1662643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2402809920).

1662643840 is an abundant number, since it is smaller than the sum of its proper divisors (3142976000).

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

1662643840 is a wasteful number, since it uses less digits than its factorization.

1662643840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571 (or 559 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 1662643840 is about 40775.5299168509. The cubic root of 1662643840 is about 1184.6764152944.

The spelling of 1662643840 in words is "one billion, six hundred sixty-two million, six hundred forty-three thousand, eight hundred forty".