400021646 has 4 divisors (see below), whose sum is σ = 600032472. Its totient is φ = 200010822.

The previous prime is 400021639. The next prime is 400021663. The reversal of 400021646 is 646120004.

It is a happy number.

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

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, 100005410 + ... + 100005413.

It is an arithmetic number, because the mean of its divisors is an integer number (150008118).

Almost surely, 2^400021646 is an apocalyptic number.

400021646 is a deficient number, since it is larger than the sum of its proper divisors (200010826).

400021646 is a wasteful number, since it uses less digits than its factorization.

400021646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200010825.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 400021646 is about 20000.5411426791. The cubic root of 400021646 is about 736.8195902460.

The spelling of 400021646 in words is "four hundred million, twenty-one thousand, six hundred forty-six".