8720691381 has 12 divisors (see below), whose sum is σ = 12609381408. Its totient is φ = 5807874024.

The previous prime is 8720691337. The next prime is 8720691389. The reversal of 8720691381 is 1831960278.

It is not a de Polignac number, because 8720691381 - 2¹⁴ = 8720674997 is a prime.

It is a super-2 number, since 2×8720691381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8720691389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 484015 + ... + 501708.

It is an arithmetic number, because the mean of its divisors is an integer number (1050781784).

Almost surely, 2^8720691381 is an apocalyptic number.

It is an amenable number.

8720691381 is a deficient number, since it is larger than the sum of its proper divisors (3888690027).

8720691381 is a wasteful number, since it uses less digits than its factorization.

8720691381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986712 (or 986709 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 8720691381 is about 93384.6421045773. The cubic root of 8720691381 is about 2058.3393299888.

The spelling of 8720691381 in words is "eight billion, seven hundred twenty million, six hundred ninety-one thousand, three hundred eighty-one".