7987921919 has 16 divisors (see below), whose sum is σ = 8401231872. Its totient is φ = 7580340768.

The previous prime is 7987921867. The next prime is 7987921969. The reversal of 7987921919 is 9191297897.

It is a cyclic number.

It is not a de Polignac number, because 7987921919 - 2⁸ = 7987921663 is a prime.

It is a super-2 number, since 2×7987921919² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7987921969) 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, 1733072 + ... + 1737674.

It is an arithmetic number, because the mean of its divisors is an integer number (525076992).

Almost surely, 2^7987921919 is an apocalyptic number.

7987921919 is a deficient number, since it is larger than the sum of its proper divisors (413309953).

7987921919 is a wasteful number, since it uses less digits than its factorization.

7987921919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5206.

The product of its digits is 5143824, while the sum is 62.

The square root of 7987921919 is about 89375.1750711572. The cubic root of 7987921919 is about 1998.9929862968.

The spelling of 7987921919 in words is "seven billion, nine hundred eighty-seven million, nine hundred twenty-one thousand, nine hundred nineteen".