21397532227 has 2 divisors, whose sum is σ = 21397532228. Its totient is φ = 21397532226.

The previous prime is 21397532207. The next prime is 21397532249. The reversal of 21397532227 is 72223579312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21397532227 is a prime.

It is not a weakly prime, because it can be changed into another prime (21397532207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10698766113 + 10698766114.

It is an arithmetic number, because the mean of its divisors is an integer number (10698766114).

Almost surely, 2^21397532227 is an apocalyptic number.

21397532227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21397532227 is an equidigital number, since it uses as much as digits as its factorization.

21397532227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 317520, while the sum is 43.

The spelling of 21397532227 in words is "twenty-one billion, three hundred ninety-seven million, five hundred thirty-two thousand, two hundred twenty-seven".