21370308987 has 8 divisors (see below), whose sum is σ = 29732603904. Its totient is φ = 13627443368.

The previous prime is 21370308943. The next prime is 21370308991. The reversal of 21370308987 is 78980307312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21370308987 - 2⁷ = 21370308859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21370308907) 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 7 ways as a sum of consecutive naturals, for example, 154857243 + ... + 154857380.

It is an arithmetic number, because the mean of its divisors is an integer number (3716575488).

Almost surely, 2^21370308987 is an apocalyptic number.

21370308987 is a deficient number, since it is larger than the sum of its proper divisors (8362294917).

21370308987 is a wasteful number, since it uses less digits than its factorization.

21370308987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309714649.

The product of its (nonzero) digits is 508032, while the sum is 48.

The spelling of 21370308987 in words is "twenty-one billion, three hundred seventy million, three hundred eight thousand, nine hundred eighty-seven".