80978731 has 4 divisors (see below), whose sum is σ = 82953864. Its totient is φ = 79003600.

The previous prime is 80978693. The next prime is 80978743. The reversal of 80978731 is 13787908.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 80978731 - 2¹⁹ = 80454443 is a prime.

It is a super-2 number, since 2×80978731² = 13115109748740722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80918731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 987505 + ... + 987586.

It is an arithmetic number, because the mean of its divisors is an integer number (20738466).

Almost surely, 2^80978731 is an apocalyptic number.

80978731 is a deficient number, since it is larger than the sum of its proper divisors (1975133).

80978731 is a wasteful number, since it uses less digits than its factorization.

80978731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1975132.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 80978731 is about 8998.8183113118. The cubic root of 80978731 is about 432.6369971522.

The spelling of 80978731 in words is "eighty million, nine hundred seventy-eight thousand, seven hundred thirty-one".