21772156571 has 8 divisors (see below), whose sum is σ = 24199584624. Its totient is φ = 19419418720.

The previous prime is 21772156559. The next prime is 21772156613. The reversal of 21772156571 is 17565127712.

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 21772156571 - 2¹⁸ = 21771894427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21772156501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18671936 + ... + 18673101.

It is an arithmetic number, because the mean of its divisors is an integer number (3024948078).

Almost surely, 2^21772156571 is an apocalyptic number.

21772156571 is a deficient number, since it is larger than the sum of its proper divisors (2427428053).

21772156571 is a wasteful number, since it uses less digits than its factorization.

21772156571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37345101.

The product of its digits is 205800, while the sum is 44.

The spelling of 21772156571 in words is "twenty-one billion, seven hundred seventy-two million, one hundred fifty-six thousand, five hundred seventy-one".