21235427531 has 2 divisors, whose sum is σ = 21235427532. Its totient is φ = 21235427530.

The previous prime is 21235427527. The next prime is 21235427581. The reversal of 21235427531 is 13572453212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21235427531 - 2² = 21235427527 is a prime.

It is a super-2 number, since 2×21235427531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21235427491 and 21235427500.

It is not a weakly prime, because it can be changed into another prime (21235427581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617713765 + 10617713766.

It is an arithmetic number, because the mean of its divisors is an integer number (10617713766).

Almost surely, 2^21235427531 is an apocalyptic number.

21235427531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21235427531 is an equidigital number, since it uses as much as digits as its factorization.

21235427531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 35.

The spelling of 21235427531 in words is "twenty-one billion, two hundred thirty-five million, four hundred twenty-seven thousand, five hundred thirty-one".