21121315325 has 72 divisors (see below), whose sum is σ = 30487111200. Its totient is φ = 14464137600.

The previous prime is 21121315307. The next prime is 21121315333. The reversal of 21121315325 is 52351312112.

It is not a de Polignac number, because 21121315325 - 2²² = 21117121021 is a prime.

It is a super-2 number, since 2×21121315325² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121315294 and 21121315303.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 10286999 + ... + 10289051.

It is an arithmetic number, because the mean of its divisors is an integer number (423432100).

Almost surely, 2^21121315325 is an apocalyptic number.

21121315325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21121315325 is a deficient number, since it is larger than the sum of its proper divisors (9365795875).

21121315325 is a wasteful number, since it uses less digits than its factorization.

21121315325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2283 (or 2267 counting only the distinct ones).

The product of its digits is 1800, while the sum is 26.

Adding to 21121315325 its reverse (52351312112), we get a palindrome (73472627437).

The spelling of 21121315325 in words is "twenty-one billion, one hundred twenty-one million, three hundred fifteen thousand, three hundred twenty-five".