56431221 has 16 divisors (see below), whose sum is σ = 93808128. Its totient is φ = 29314800.

The previous prime is 56431189. The next prime is 56431223. The reversal of 56431221 is 12213465.

It is not a de Polignac number, because 56431221 - 2⁵ = 56431189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 56431191 and 56431200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56431223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121915 + ... + 122376.

It is an arithmetic number, because the mean of its divisors is an integer number (5863008).

Almost surely, 2^56431221 is an apocalyptic number.

It is an amenable number.

56431221 is a deficient number, since it is larger than the sum of its proper divisors (37376907).

56431221 is a wasteful number, since it uses less digits than its factorization.

56431221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244312.

The product of its digits is 1440, while the sum is 24.

The square root of 56431221 is about 7512.0716849615. The cubic root of 56431221 is about 383.5657458079.

Adding to 56431221 its reverse (12213465), we get a palindrome (68644686).

The spelling of 56431221 in words is "fifty-six million, four hundred thirty-one thousand, two hundred twenty-one".