21788621597 has 8 divisors (see below), whose sum is σ = 22156545600. Its totient is φ = 21423433504.

The previous prime is 21788621593. The next prime is 21788621611. The reversal of 21788621597 is 79512688712.

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

It is not a de Polignac number, because 21788621597 - 2² = 21788621593 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21788621593) 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, 667913 + ... + 699774.

It is an arithmetic number, because the mean of its divisors is an integer number (2769568200).

Almost surely, 2^21788621597 is an apocalyptic number.

It is an amenable number.

21788621597 is a deficient number, since it is larger than the sum of its proper divisors (367924003).

21788621597 is a wasteful number, since it uses less digits than its factorization.

21788621597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1367955.

The product of its digits is 3386880, while the sum is 56.

The spelling of 21788621597 in words is "twenty-one billion, seven hundred eighty-eight million, six hundred twenty-one thousand, five hundred ninety-seven".