64221431 has 2 divisors, whose sum is σ = 64221432. Its totient is φ = 64221430.

The previous prime is 64221419. The next prime is 64221433. The reversal of 64221431 is 13412246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64221431 - 2²² = 60027127 is a prime.

It is a super-2 number, since 2×64221431² = 8248784399375522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 64221433, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 64221397 and 64221406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64221433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32110715 + 32110716.

It is an arithmetic number, because the mean of its divisors is an integer number (32110716).

Almost surely, 2^64221431 is an apocalyptic number.

64221431 is a deficient number, since it is larger than the sum of its proper divisors (1).

64221431 is an equidigital number, since it uses as much as digits as its factorization.

64221431 is an evil number, because the sum of its binary digits is even.

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

The square root of 64221431 is about 8013.8274875368. The cubic root of 64221431 is about 400.4607835758.

Adding to 64221431 its reverse (13412246), we get a palindrome (77633677).

The spelling of 64221431 in words is "sixty-four million, two hundred twenty-one thousand, four hundred thirty-one".