21345523051 has 16 divisors (see below), whose sum is σ = 23409345600. Its totient is φ = 19373211648.

The previous prime is 21345523049. The next prime is 21345523057. The reversal of 21345523051 is 15032554312.

It is a cyclic number.

It is not a de Polignac number, because 21345523051 - 2¹ = 21345523049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21345523057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 379435 + ... + 432043.

It is an arithmetic number, because the mean of its divisors is an integer number (1463084100).

Almost surely, 2^21345523051 is an apocalyptic number.

21345523051 is a deficient number, since it is larger than the sum of its proper divisors (2063822549).

21345523051 is a wasteful number, since it uses less digits than its factorization.

21345523051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53478.

The product of its (nonzero) digits is 18000, while the sum is 31.

The spelling of 21345523051 in words is "twenty-one billion, three hundred forty-five million, five hundred twenty-three thousand, fifty-one".