400221537 has 16 divisors (see below), whose sum is σ = 537825600. Its totient is φ = 264724992.

The previous prime is 400221527. The next prime is 400221539. The reversal of 400221537 is 735122004.

It is not a de Polignac number, because 400221537 - 2⁶ = 400221473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (400221539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234714 + ... + 236412.

It is an arithmetic number, because the mean of its divisors is an integer number (33614100).

Almost surely, 2^400221537 is an apocalyptic number.

It is an amenable number.

400221537 is a deficient number, since it is larger than the sum of its proper divisors (137604063).

400221537 is a wasteful number, since it uses less digits than its factorization.

400221537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2272.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 400221537 is about 20005.5376583585. The cubic root of 400221537 is about 736.9422995047.

The spelling of 400221537 in words is "four hundred million, two hundred twenty-one thousand, five hundred thirty-seven".