21633221247387 has 32 divisors (see below), whose sum is σ = 29114305059840. Its totient is φ = 14287609211040.

The previous prime is 21633221247317. The next prime is 21633221247403. The reversal of 21633221247387 is 78374212233612.

It is not a de Polignac number, because 21633221247387 - 2¹⁰ = 21633221246363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21633221247317) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 644538868 + ... + 644572430.

It is an arithmetic number, because the mean of its divisors is an integer number (909822033120).

Almost surely, 2^{21633221247387} is an apocalyptic number.

21633221247387 is a deficient number, since it is larger than the sum of its proper divisors (7481083812453).

21633221247387 is a wasteful number, since it uses less digits than its factorization.

21633221247387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36983.

The product of its digits is 4064256, while the sum is 51.

The spelling of 21633221247387 in words is "twenty-one trillion, six hundred thirty-three billion, two hundred twenty-one million, two hundred forty-seven thousand, three hundred eighty-seven".