21385315087 has 16 divisors (see below), whose sum is σ = 23208891552. Its totient is φ = 19626163200.

The previous prime is 21385315073. The next prime is 21385315109. The reversal of 21385315087 is 78051358312.

It is not a de Polignac number, because 21385315087 - 2¹¹ = 21385313039 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385315057) 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 15 ways as a sum of consecutive naturals, for example, 414993 + ... + 463669.

It is an arithmetic number, because the mean of its divisors is an integer number (1450555722).

Almost surely, 2^21385315087 is an apocalyptic number.

21385315087 is a deficient number, since it is larger than the sum of its proper divisors (1823576465).

21385315087 is a wasteful number, since it uses less digits than its factorization.

21385315087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49338.

The product of its (nonzero) digits is 201600, while the sum is 43.

The spelling of 21385315087 in words is "twenty-one billion, three hundred eighty-five million, three hundred fifteen thousand, eighty-seven".