21121450315 has 32 divisors (see below), whose sum is σ = 29380216320. Its totient is φ = 14277225984.

The previous prime is 21121450289. The next prime is 21121450319. The reversal of 21121450315 is 51305412112.

It is not a de Polignac number, because 21121450315 - 2⁵ = 21121450283 is a prime.

It is a super-2 number, since 2×21121450315² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121450315.

It is not an unprimeable number, because it can be changed into a prime (21121450319) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1348851 + ... + 1364419.

It is an arithmetic number, because the mean of its divisors is an integer number (918131760).

Almost surely, 2^21121450315 is an apocalyptic number.

21121450315 is a deficient number, since it is larger than the sum of its proper divisors (8258766005).

21121450315 is a wasteful number, since it uses less digits than its factorization.

21121450315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16131.

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 21121450315 its reverse (51305412112), we get a palindrome (72426862427).

The spelling of 21121450315 in words is "twenty-one billion, one hundred twenty-one million, four hundred fifty thousand, three hundred fifteen".