640620105 has 32 divisors (see below), whose sum is σ = 1051674624. Its totient is φ = 332838336.

The previous prime is 640620077. The next prime is 640620119. The reversal of 640620105 is 501026046.

It is a de Polignac number, because none of the positive numbers 2^k-640620105 is a prime.

It is a super-2 number, since 2×640620105² = 820788237860422050, which contains 22 as substring.

It is a Curzon number.

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, 158034 + ... + 162036.

It is an arithmetic number, because the mean of its divisors is an integer number (32864832).

Almost surely, 2^640620105 is an apocalyptic number.

It is an amenable number.

640620105 is a deficient number, since it is larger than the sum of its proper divisors (411054519).

640620105 is a wasteful number, since it uses less digits than its factorization.

640620105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4285.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 640620105 is about 25310.4742152335. The cubic root of 640620105 is about 862.0521144448.

The spelling of 640620105 in words is "six hundred forty million, six hundred twenty thousand, one hundred five".