21936816475 has 24 divisors (see below), whose sum is σ = 31099953920. Its totient is φ = 15036412320.

The previous prime is 21936816431. The next prime is 21936816479. The reversal of 21936816475 is 57461863912.

It is not a de Polignac number, because 21936816475 - 2¹⁵ = 21936783707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21936816479) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 441754 + ... + 488896.

Almost surely, 2^21936816475 is an apocalyptic number.

21936816475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21936816475 is a deficient number, since it is larger than the sum of its proper divisors (9163137445).

21936816475 is a wasteful number, since it uses less digits than its factorization.

21936816475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49819 (or 49814 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 52.

The spelling of 21936816475 in words is "twenty-one billion, nine hundred thirty-six million, eight hundred sixteen thousand, four hundred seventy-five".