21515157459 has 12 divisors (see below), whose sum is σ = 31397837016. Its totient is φ = 14195567232.

The previous prime is 21515157437. The next prime is 21515157511. The reversal of 21515157459 is 95475151512.

21515157459 is a `hidden beast` number, since 2 + 1 + 515 + 15 + 74 + 59 = 666.

It is not a de Polignac number, because 21515157459 - 2⁷ = 21515157331 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21515157659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12321669 + ... + 12323414.

It is an arithmetic number, because the mean of its divisors is an integer number (2616486418).

Almost surely, 2^21515157459 is an apocalyptic number.

21515157459 is a deficient number, since it is larger than the sum of its proper divisors (9882679557).

21515157459 is a wasteful number, since it uses less digits than its factorization.

21515157459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24645186 (or 24645183 counting only the distinct ones).

The product of its digits is 315000, while the sum is 45.

The spelling of 21515157459 in words is "twenty-one billion, five hundred fifteen million, one hundred fifty-seven thousand, four hundred fifty-nine".