80961805 has 8 divisors (see below), whose sum is σ = 97579800. Its totient is φ = 64485696.

The previous prime is 80961761. The next prime is 80961833. The reversal of 80961805 is 50816908.

It can be written as a sum of positive squares in 4 ways, for example, as 49028004 + 31933801 = 7002^2 + 5651^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 80961805 - 2²³ = 72573197 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34210 + ... + 36499.

It is an arithmetic number, because the mean of its divisors is an integer number (12197475).

Almost surely, 2^80961805 is an apocalyptic number.

It is an amenable number.

80961805 is a deficient number, since it is larger than the sum of its proper divisors (16617995).

80961805 is a wasteful number, since it uses less digits than its factorization.

80961805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70943.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 80961805 is about 8997.8778053494. The cubic root of 80961805 is about 432.6068521006.

The spelling of 80961805 in words is "eighty million, nine hundred sixty-one thousand, eight hundred five".