21040525215 has 24 divisors (see below), whose sum is σ = 36732630480. Its totient is φ = 11140879104.

The previous prime is 21040525147. The next prime is 21040525217. The reversal of 21040525215 is 51252504012.

21040525215 is a `hidden beast` number, since 2 + 1 + 0 + 405 + 252 + 1 + 5 = 666.

It is not a de Polignac number, because 21040525215 - 2¹¹ = 21040523167 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21040525217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1675642 + ... + 1688151.

It is an arithmetic number, because the mean of its divisors is an integer number (1530526270).

Almost surely, 2^21040525215 is an apocalyptic number.

21040525215 is a deficient number, since it is larger than the sum of its proper divisors (15692105265).

21040525215 is a wasteful number, since it uses less digits than its factorization.

21040525215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3363943 (or 3363940 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The spelling of 21040525215 in words is "twenty-one billion, forty million, five hundred twenty-five thousand, two hundred fifteen".