8042720091 has 16 divisors (see below), whose sum is σ = 12257856000. Its totient is φ = 4594984128.

The previous prime is 8042720087. The next prime is 8042720093. The reversal of 8042720091 is 1900272408.

It is a happy number.

It is not a de Polignac number, because 8042720091 - 2² = 8042720087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8042720093) 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, 90090 + ... + 155568.

It is an arithmetic number, because the mean of its divisors is an integer number (766116000).

Almost surely, 2^8042720091 is an apocalyptic number.

8042720091 is a deficient number, since it is larger than the sum of its proper divisors (4215135909).

8042720091 is a wasteful number, since it uses less digits than its factorization.

8042720091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71338.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 8042720091 is about 89681.2137016443. The cubic root of 8042720091 is about 2003.5536894890.

Adding to 8042720091 its reverse (1900272408), we get a palindrome (9942992499).

The spelling of 8042720091 in words is "eight billion, forty-two million, seven hundred twenty thousand, ninety-one".