21188762985 has 16 divisors (see below), whose sum is σ = 36509868864. Its totient is φ = 10431390912.

The previous prime is 21188762963. The next prime is 21188763017. The reversal of 21188762985 is 58926788112.

It is not a de Polignac number, because 21188762985 - 2¹⁰ = 21188761961 is a prime.

It is a super-2 number, since 2×21188762985² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54329967 + ... + 54330356.

It is an arithmetic number, because the mean of its divisors is an integer number (2281866804).

Almost surely, 2^21188762985 is an apocalyptic number.

It is an amenable number.

21188762985 is a deficient number, since it is larger than the sum of its proper divisors (15321105879).

21188762985 is a wasteful number, since it uses less digits than its factorization.

21188762985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108660344.

The product of its digits is 3870720, while the sum is 57.

The spelling of 21188762985 in words is "twenty-one billion, one hundred eighty-eight million, seven hundred sixty-two thousand, nine hundred eighty-five".