21956215494 has 8 divisors (see below), whose sum is σ = 43912431000. Its totient is φ = 7318738496.

The previous prime is 21956215483. The next prime is 21956215507. The reversal of 21956215494 is 49451265912.

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

21956215494 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1829684619 + ... + 1829684630.

It is an arithmetic number, because the mean of its divisors is an integer number (5489053875).

Almost surely, 2^21956215494 is an apocalyptic number.

21956215494 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21956215494 is a wasteful number, since it uses less digits than its factorization.

21956215494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3659369254.

The product of its digits is 777600, while the sum is 48.

The spelling of 21956215494 in words is "twenty-one billion, nine hundred fifty-six million, two hundred fifteen thousand, four hundred ninety-four".