1640622555 has 96 divisors (see below), whose sum is σ = 3360756672. Its totient is φ = 729907200.

The previous prime is 1640622551. The next prime is 1640622589. The reversal of 1640622555 is 5552260461.

1640622555 is a `hidden beast` number, since 1 + 6 + 40 + 62 + 2 + 555 = 666.

It is not a de Polignac number, because 1640622555 - 2² = 1640622551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1640622551) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1241295 + ... + 1242615.

It is an arithmetic number, because the mean of its divisors is an integer number (35007882).

Almost surely, 2^1640622555 is an apocalyptic number.

1640622555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1640622555 is an abundant number, since it is smaller than the sum of its proper divisors (1720134117).

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

1640622555 is a wasteful number, since it uses less digits than its factorization.

1640622555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1549 (or 1546 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The square root of 1640622555 is about 40504.5991833026. The cubic root of 1640622555 is about 1179.4229091862.

The spelling of 1640622555 in words is "one billion, six hundred forty million, six hundred twenty-two thousand, five hundred fifty-five".