20867928971 has 4 divisors (see below), whose sum is σ = 20875381944. Its totient is φ = 20860476000.

The previous prime is 20867928967. The next prime is 20867928989. The reversal of 20867928971 is 17982976802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20867928971 - 2² = 20867928967 is a prime.

It is a super-2 number, since 2×20867928971² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20867928971.

It is not an unprimeable number, because it can be changed into a prime (20867928271) 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, 3722285 + ... + 3727886.

It is an arithmetic number, because the mean of its divisors is an integer number (5218845486).

Almost surely, 2^20867928971 is an apocalyptic number.

20867928971 is a deficient number, since it is larger than the sum of its proper divisors (7452973).

20867928971 is an equidigital number, since it uses as much as digits as its factorization.

20867928971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7452972.

The product of its (nonzero) digits is 6096384, while the sum is 59.

The spelling of 20867928971 in words is "twenty billion, eight hundred sixty-seven million, nine hundred twenty-eight thousand, nine hundred seventy-one".