405640655 has 32 divisors (see below), whose sum is σ = 590488704. Its totient is φ = 261144576.

The previous prime is 405640649. The next prime is 405640663. The reversal of 405640655 is 556046504.

It is not a de Polignac number, because 405640655 - 2⁴ = 405640639 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is a congruent 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, 399929 + ... + 400941.

It is an arithmetic number, because the mean of its divisors is an integer number (18452772).

Almost surely, 2^405640655 is an apocalyptic number.

405640655 is a deficient number, since it is larger than the sum of its proper divisors (184848049).

405640655 is a wasteful number, since it uses less digits than its factorization.

405640655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715.

The product of its (nonzero) digits is 72000, while the sum is 35.

The square root of 405640655 is about 20140.5227092049. The cubic root of 405640655 is about 740.2535380318.

The spelling of 405640655 in words is "four hundred five million, six hundred forty thousand, six hundred fifty-five".