21207677187 has 8 divisors (see below), whose sum is σ = 28450381504. Its totient is φ = 14051712168.

The previous prime is 21207677173. The next prime is 21207677201. The reversal of 21207677187 is 78177670212.

It is an interprime number because it is at equal distance from previous prime (21207677173) and next prime (21207677201).

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

It is not a de Polignac number, because 21207677187 - 2⁴ = 21207677171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21207677087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21684253 + ... + 21685230.

It is an arithmetic number, because the mean of its divisors is an integer number (3556297688).

Almost surely, 2^21207677187 is an apocalyptic number.

21207677187 is a deficient number, since it is larger than the sum of its proper divisors (7242704317).

21207677187 is a wasteful number, since it uses less digits than its factorization.

21207677187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43369649.

The product of its (nonzero) digits is 460992, while the sum is 48.

The spelling of 21207677187 in words is "twenty-one billion, two hundred seven million, six hundred seventy-seven thousand, one hundred eighty-seven".