21947237315 has 8 divisors (see below), whose sum is σ = 26337751440. Its totient is φ = 17557078752.

The previous prime is 21947237287. The next prime is 21947237329. The reversal of 21947237315 is 51373274912.

It is a Cunningham number, because it is equal to 148146²-1.

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

It is a cyclic number.

It is not a de Polignac number, because 21947237315 - 2¹² = 21947233219 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74072 + ... + 222218.

It is an arithmetic number, because the mean of its divisors is an integer number (3292218930).

Almost surely, 2^21947237315 is an apocalyptic number.

21947237315 is a deficient number, since it is larger than the sum of its proper divisors (4390514125).

21947237315 is a wasteful number, since it uses less digits than its factorization.

21947237315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177781.

The product of its digits is 317520, while the sum is 44.

The spelling of 21947237315 in words is "twenty-one billion, nine hundred forty-seven million, two hundred thirty-seven thousand, three hundred fifteen".