1640643610 has 32 divisors (see below), whose sum is σ = 3020256720. Its totient is φ = 641507328.

The previous prime is 1640643583. The next prime is 1640643611. The reversal of 1640643610 is 163460461.

It can be written as a sum of positive squares in 8 ways, for example, as 671379921 + 969263689 = 25911^2 + 31133^2 .

It is a super-2 number, since 2×1640643610² = 5383422910067664200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1640643611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72546 + ... + 92434.

Almost surely, 2^1640643610 is an apocalyptic number.

1640643610 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1640643610 is a deficient number, since it is larger than the sum of its proper divisors (1379613110).

1640643610 is a wasteful number, since it uses less digits than its factorization.

1640643610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20082.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 1640643610 is about 40504.8590912251. The cubic root of 1640643610 is about 1179.4279545561.

The spelling of 1640643610 in words is "one billion, six hundred forty million, six hundred forty-three thousand, six hundred ten".