7919051721 has 16 divisors (see below), whose sum is σ = 12483235200. Its totient is φ = 4369131648.

The previous prime is 7919051653. The next prime is 7919051729. The reversal of 7919051721 is 1271509197.

It is not a de Polignac number, because 7919051721 - 2⁹ = 7919051209 is a prime.

It is a super-2 number, since 2×7919051721² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7919051729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6501076 + ... + 6502293.

It is an arithmetic number, because the mean of its divisors is an integer number (780202200).

Almost surely, 2^7919051721 is an apocalyptic number.

It is an amenable number.

7919051721 is a deficient number, since it is larger than the sum of its proper divisors (4564183479).

7919051721 is a wasteful number, since it uses less digits than its factorization.

7919051721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13003408.

The product of its (nonzero) digits is 39690, while the sum is 42.

The square root of 7919051721 is about 88989.0539392346. The cubic root of 7919051721 is about 1993.2314291487.

The spelling of 7919051721 in words is "seven billion, nine hundred nineteen million, fifty-one thousand, seven hundred twenty-one".