80521657 has 4 divisors (see below), whose sum is σ = 82697956. Its totient is φ = 78345360.

The previous prime is 80521633. The next prime is 80521687. The reversal of 80521657 is 75612508.

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

It can be written as a sum of positive squares in 2 ways, for example, as 55711296 + 24810361 = 7464^2 + 4981^2 .

It is a cyclic number.

It is not a de Polignac number, because 80521657 - 2¹⁹ = 79997369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80521627) 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, 1088094 + ... + 1088167.

It is an arithmetic number, because the mean of its divisors is an integer number (20674489).

Almost surely, 2^80521657 is an apocalyptic number.

It is an amenable number.

80521657 is a deficient number, since it is larger than the sum of its proper divisors (2176299).

80521657 is a wasteful number, since it uses less digits than its factorization.

80521657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2176298.

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 80521657 is about 8973.3860387258. The cubic root of 80521657 is about 431.8214729433.

The spelling of 80521657 in words is "eighty million, five hundred twenty-one thousand, six hundred fifty-seven".