21772271808 has 84 divisors (see below), whose sum is σ = 71321482960. Its totient is φ = 6220647936.

The previous prime is 21772271803. The next prime is 21772271809. The reversal of 21772271808 is 80817227712.

It is a tau number, because it is divible by the number of its divisors (84).

It is not an unprimeable number, because it can be changed into a prime (21772271803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2695903 + ... + 2703966.

Almost surely, 2^21772271808 is an apocalyptic number.

21772271808 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21772271808 is an abundant number, since it is smaller than the sum of its proper divisors (49549211152).

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

21772271808 is a wasteful number, since it uses less digits than its factorization.

21772271808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5399894 (or 5399881 counting only the distinct ones).

The product of its (nonzero) digits is 175616, while the sum is 45.

The spelling of 21772271808 in words is "twenty-one billion, seven hundred seventy-two million, two hundred seventy-one thousand, eight hundred eight".