21946172379 has 8 divisors (see below), whose sum is σ = 29530018320. Its totient is φ = 14496554016.

The previous prime is 21946172329. The next prime is 21946172399. The reversal of 21946172379 is 97327164912.

It is a happy number.

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

It is not a de Polignac number, because 21946172379 - 2⁸ = 21946172123 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21946172329) 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, 33556512 + ... + 33557165.

It is an arithmetic number, because the mean of its divisors is an integer number (3691252290).

Almost surely, 2^21946172379 is an apocalyptic number.

21946172379 is a deficient number, since it is larger than the sum of its proper divisors (7583845941).

21946172379 is a wasteful number, since it uses less digits than its factorization.

21946172379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67113789.

The product of its digits is 1143072, while the sum is 51.

The spelling of 21946172379 in words is "twenty-one billion, nine hundred forty-six million, one hundred seventy-two thousand, three hundred seventy-nine".