400871638 has 4 divisors (see below), whose sum is σ = 601307460. Its totient is φ = 200435818.

The previous prime is 400871573. The next prime is 400871641. The reversal of 400871638 is 836178004.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 400871597 and 400871606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100217908 + ... + 100217911.

It is an arithmetic number, because the mean of its divisors is an integer number (150326865).

Almost surely, 2^400871638 is an apocalyptic number.

400871638 is a deficient number, since it is larger than the sum of its proper divisors (200435822).

400871638 is a wasteful number, since it uses less digits than its factorization.

400871638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200435821.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 400871638 is about 20021.7790917790. The cubic root of 400871638 is about 737.3411017624.

The spelling of 400871638 in words is "four hundred million, eight hundred seventy-one thousand, six hundred thirty-eight".