3972920051921 has 8 divisors (see below), whose sum is σ = 3995268076800. Its totient is φ = 3950576403120.

The previous prime is 3972920051909. The next prime is 3972920051929. The reversal of 3972920051921 is 1291500292793.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3972920051921 is a prime.

It is a super-2 number, since 2×3972920051921² (a number of 26 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 3972920051921.

It is not an unprimeable number, because it can be changed into a prime (3972920051929) 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, 735410 + ... + 2913188.

It is an arithmetic number, because the mean of its divisors is an integer number (499408509600).

Almost surely, 2^{3972920051921} is an apocalyptic number.

It is an amenable number.

3972920051921 is a deficient number, since it is larger than the sum of its proper divisors (22348024879).

3972920051921 is a wasteful number, since it uses less digits than its factorization.

3972920051921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2188039.

The product of its (nonzero) digits is 612360, while the sum is 50.

The spelling of 3972920051921 in words is "three trillion, nine hundred seventy-two billion, nine hundred twenty million, fifty-one thousand, nine hundred twenty-one".