21972787199 has 16 divisors (see below), whose sum is σ = 24597802656. Its totient is φ = 19454054400.

The previous prime is 21972787189. The next prime is 21972787201. The reversal of 21972787199 is 99178727912.

It is a happy number.

It is not a de Polignac number, because 21972787199 - 2⁴ = 21972787183 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 (21972787169) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 218009 + ... + 302445.

It is an arithmetic number, because the mean of its divisors is an integer number (1537362666).

Almost surely, 2^21972787199 is an apocalyptic number.

21972787199 is a deficient number, since it is larger than the sum of its proper divisors (2625015457).

21972787199 is a wasteful number, since it uses less digits than its factorization.

21972787199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85066.

The product of its digits is 8001504, while the sum is 62.

The spelling of 21972787199 in words is "twenty-one billion, nine hundred seventy-two million, seven hundred eighty-seven thousand, one hundred ninety-nine".