21233371251 has 4 divisors (see below), whose sum is σ = 28311161672. Its totient is φ = 14155580832.

The previous prime is 21233371241. The next prime is 21233371309. The reversal of 21233371251 is 15217333212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21233371251 - 2¹⁹ = 21232846963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21233371231) 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, 3538895206 + ... + 3538895211.

It is an arithmetic number, because the mean of its divisors is an integer number (7077790418).

Almost surely, 2^21233371251 is an apocalyptic number.

21233371251 is a deficient number, since it is larger than the sum of its proper divisors (7077790421).

21233371251 is an equidigital number, since it uses as much as digits as its factorization.

21233371251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7077790420.

The product of its digits is 7560, while the sum is 30.

The spelling of 21233371251 in words is "twenty-one billion, two hundred thirty-three million, three hundred seventy-one thousand, two hundred fifty-one".