406621638 has 24 divisors (see below), whose sum is σ = 904826208. Its totient is φ = 131877072.

The previous prime is 406621571. The next prime is 406621639. The reversal of 406621638 is 836126604.

406621638 is a `hidden beast` number, since 406 + 6 + 216 + 38 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406621639) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 304606 + ... + 305937.

It is an arithmetic number, because the mean of its divisors is an integer number (37701092).

Almost surely, 2^406621638 is an apocalyptic number.

406621638 is an abundant number, since it is smaller than the sum of its proper divisors (498204570).

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

406621638 is a wasteful number, since it uses less digits than its factorization.

406621638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610588 (or 610585 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 406621638 is about 20164.8614674141. The cubic root of 406621638 is about 740.8497895243.

The spelling of 406621638 in words is "four hundred six million, six hundred twenty-one thousand, six hundred thirty-eight".