642697605 has 32 divisors (see below), whose sum is σ = 1246446720. Its totient is φ = 311610240.

The previous prime is 642697603. The next prime is 642697639. The reversal of 642697605 is 506796246.

It is not a de Polignac number, because 642697605 - 2¹ = 642697603 is a prime.

It is a super-2 number, since 2×642697605² = 826120422945472050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642697603) 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, 214912 + ... + 217881.

It is an arithmetic number, because the mean of its divisors is an integer number (38951460).

Almost surely, 2^642697605 is an apocalyptic number.

It is an amenable number.

642697605 is a deficient number, since it is larger than the sum of its proper divisors (603749115).

642697605 is a wasteful number, since it uses less digits than its factorization.

642697605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432818 (or 432812 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 642697605 is about 25351.4813176666. The cubic root of 642697605 is about 862.9829733557.

It can be divided in two parts, 64269 and 7605, that multiplied together give a triangular number (488765745 = T₃₁₂₆₅).

The spelling of 642697605 in words is "six hundred forty-two million, six hundred ninety-seven thousand, six hundred five".