21922809381 has 16 divisors (see below), whose sum is σ = 35430803520. Its totient is φ = 13286550960.

The previous prime is 21922809379. The next prime is 21922809407. The reversal of 21922809381 is 18390822912.

It is a happy number.

21922809381 is a `hidden beast` number, since 2 + 192 + 2 + 80 + 9 + 381 = 666.

It is not a de Polignac number, because 21922809381 - 2¹ = 21922809379 is a prime.

It is a super-2 number, since 2×21922809381² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21922809281) 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, 36906790 + ... + 36907383.

It is an arithmetic number, because the mean of its divisors is an integer number (2214425220).

Almost surely, 2^21922809381 is an apocalyptic number.

It is an amenable number.

21922809381 is a deficient number, since it is larger than the sum of its proper divisors (13507994139).

21922809381 is a wasteful number, since it uses less digits than its factorization.

21922809381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73814193 (or 73814187 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 21922809381 in words is "twenty-one billion, nine hundred twenty-two million, eight hundred nine thousand, three hundred eighty-one".