21671126972 has 48 divisors (see below), whose sum is σ = 42758876160. Its totient is φ = 9521116800.

The previous prime is 21671126927. The next prime is 21671126987. The reversal of 21671126972 is 27962117612.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1159679 + ... + 1178217.

It is an arithmetic number, because the mean of its divisors is an integer number (890809920).

Almost surely, 2^21671126972 is an apocalyptic number.

21671126972 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21671126972 is a deficient number, since it is larger than the sum of its proper divisors (21087749188).

21671126972 is a wasteful number, since it uses less digits than its factorization.

21671126972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19442 (or 19440 counting only the distinct ones).

The product of its digits is 127008, while the sum is 44.

The spelling of 21671126972 in words is "twenty-one billion, six hundred seventy-one million, one hundred twenty-six thousand, nine hundred seventy-two".