400220531 has 4 divisors (see below), whose sum is σ = 400587792. Its totient is φ = 399853272.

The previous prime is 400220521. The next prime is 400220533. The reversal of 400220531 is 135022004.

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

It is a cyclic number.

It is not a de Polignac number, because 400220531 - 2⁶ = 400220467 is a prime.

It is a super-2 number, since 2×400220531² = 320352946867843922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400220533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181991 + ... + 184176.

It is an arithmetic number, because the mean of its divisors is an integer number (100146948).

Almost surely, 2^400220531 is an apocalyptic number.

400220531 is a deficient number, since it is larger than the sum of its proper divisors (367261).

400220531 is a wasteful number, since it uses less digits than its factorization.

400220531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367260.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 400220531 is about 20005.5125153044. The cubic root of 400220531 is about 736.9416820429.

Adding to 400220531 its reverse (135022004), we get a palindrome (535242535).

The spelling of 400220531 in words is "four hundred million, two hundred twenty thousand, five hundred thirty-one".