21130252433 has 4 divisors (see below), whose sum is σ = 21579832320. Its totient is φ = 20680672548.

The previous prime is 21130252399. The next prime is 21130252483. The reversal of 21130252433 is 33425203112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21130252433 - 2²⁴ = 21113475217 is a prime.

It is a super-4 number, since 4×21130252433⁴ (a number of 42 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21130252483) 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, 224789873 + ... + 224789966.

It is an arithmetic number, because the mean of its divisors is an integer number (5394958080).

Almost surely, 2^21130252433 is an apocalyptic number.

It is an amenable number.

21130252433 is a deficient number, since it is larger than the sum of its proper divisors (449579887).

21130252433 is an equidigital number, since it uses as much as digits as its factorization.

21130252433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449579886.

The product of its (nonzero) digits is 4320, while the sum is 26.

Adding to 21130252433 its reverse (33425203112), we get a palindrome (54555455545).

The spelling of 21130252433 in words is "twenty-one billion, one hundred thirty million, two hundred fifty-two thousand, four hundred thirty-three".