21923081690 has 8 divisors (see below), whose sum is σ = 39461547060. Its totient is φ = 8769232672.

The previous prime is 21923081689. The next prime is 21923081693. The reversal of 21923081690 is 9618032912.

It can be written as a sum of positive squares in 2 ways, for example, as 20810659081 + 1112422609 = 144259^2 + 33353^2 .

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

It is a super-2 number, since 2×21923081690² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21923081693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1096154075 + ... + 1096154094.

Almost surely, 2^21923081690 is an apocalyptic number.

21923081690 is a deficient number, since it is larger than the sum of its proper divisors (17538465370).

21923081690 is a wasteful number, since it uses less digits than its factorization.

21923081690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2192308176.

The product of its (nonzero) digits is 46656, while the sum is 41.

The spelling of 21923081690 in words is "twenty-one billion, nine hundred twenty-three million, eighty-one thousand, six hundred ninety".