21213753587 has 4 divisors (see below), whose sum is σ = 22845580800. Its totient is φ = 19581926376.

The previous prime is 21213753581. The next prime is 21213753653. The reversal of 21213753587 is 78535731212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21213753587 - 2⁴ = 21213753571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21213753581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815913587 + ... + 815913612.

It is an arithmetic number, because the mean of its divisors is an integer number (5711395200).

Almost surely, 2^21213753587 is an apocalyptic number.

21213753587 is a deficient number, since it is larger than the sum of its proper divisors (1631827213).

21213753587 is a wasteful number, since it uses less digits than its factorization.

21213753587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631827212.

The product of its digits is 352800, while the sum is 44.

The spelling of 21213753587 in words is "twenty-one billion, two hundred thirteen million, seven hundred fifty-three thousand, five hundred eighty-seven".