21523150051 has 4 divisors (see below), whose sum is σ = 23178776992. Its totient is φ = 19867523112.

The previous prime is 21523150037. The next prime is 21523150069. The reversal of 21523150051 is 15005132512.

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

It is a cyclic number.

It is not a de Polignac number, because 21523150051 - 2²¹ = 21521052899 is a prime.

It is a super-2 number, since 2×21523150051² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21523149998 and 21523150025.

It is not an unprimeable number, because it can be changed into a prime (21523150031) 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, 827813451 + ... + 827813476.

It is an arithmetic number, because the mean of its divisors is an integer number (5794694248).

Almost surely, 2^21523150051 is an apocalyptic number.

21523150051 is a deficient number, since it is larger than the sum of its proper divisors (1655626941).

21523150051 is a wasteful number, since it uses less digits than its factorization.

21523150051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1655626940.

The product of its (nonzero) digits is 1500, while the sum is 25.

Adding to 21523150051 its reverse (15005132512), we get a palindrome (36528282563).

The spelling of 21523150051 in words is "twenty-one billion, five hundred twenty-three million, one hundred fifty thousand, fifty-one".