21031254051 has 16 divisors (see below), whose sum is σ = 28244498688. Its totient is φ = 13919631200.

The previous prime is 21031254043. The next prime is 21031254059. The reversal of 21031254051 is 15045213012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21031254043) and next prime (21031254059).

It is a cyclic number.

It is not a de Polignac number, because 21031254051 - 2³ = 21031254043 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21031254059) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 385756 + ... + 436886.

It is an arithmetic number, because the mean of its divisors is an integer number (1765281168).

Almost surely, 2^21031254051 is an apocalyptic number.

21031254051 is a deficient number, since it is larger than the sum of its proper divisors (7213244637).

21031254051 is a wasteful number, since it uses less digits than its factorization.

21031254051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52122.

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 21031254051 its reverse (15045213012), we get a palindrome (36076467063).

The spelling of 21031254051 in words is "twenty-one billion, thirty-one million, two hundred fifty-four thousand, fifty-one".