21242351254 has 16 divisors (see below), whose sum is σ = 31959119808. Its totient is φ = 10589337792.

The previous prime is 21242351239. The next prime is 21242351261. The reversal of 21242351254 is 45215324212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2072787 + ... + 2083009.

It is an arithmetic number, because the mean of its divisors is an integer number (1997444988).

Almost surely, 2^21242351254 is an apocalyptic number.

21242351254 is a deficient number, since it is larger than the sum of its proper divisors (10716768554).

21242351254 is a wasteful number, since it uses less digits than its factorization.

21242351254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13239.

The product of its digits is 19200, while the sum is 31.

Adding to 21242351254 its reverse (45215324212), we get a palindrome (66457675466).

The spelling of 21242351254 in words is "twenty-one billion, two hundred forty-two million, three hundred fifty-one thousand, two hundred fifty-four".