21246555525 has 48 divisors (see below), whose sum is σ = 37847160960. Its totient is φ = 10455033600.

The previous prime is 21246555521. The next prime is 21246555559. The reversal of 21246555525 is 52555564212.

It is a happy number.

It is not a de Polignac number, because 21246555525 - 2² = 21246555521 is a prime.

It is a super-2 number, since 2×21246555525² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21246555521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3107811 + ... + 3114639.

It is an arithmetic number, because the mean of its divisors is an integer number (788482520).

Almost surely, 2^21246555525 is an apocalyptic number.

21246555525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21246555525 is a deficient number, since it is larger than the sum of its proper divisors (16600605435).

21246555525 is a wasteful number, since it uses less digits than its factorization.

21246555525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10046 (or 10041 counting only the distinct ones).

The product of its digits is 600000, while the sum is 42.

The spelling of 21246555525 in words is "twenty-one billion, two hundred forty-six million, five hundred fifty-five thousand, five hundred twenty-five".