813973957 has 4 divisors (see below), whose sum is σ = 861854796. Its totient is φ = 766093120.

The previous prime is 813973921. The next prime is 813973969. The reversal of 813973957 is 759379318.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 759379318 = 2 ⋅379689659.

It can be written as a sum of positive squares in 2 ways, for example, as 723932836 + 90041121 = 26906^2 + 9489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-813973957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813973907) 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, 23940394 + ... + 23940427.

It is an arithmetic number, because the mean of its divisors is an integer number (215463699).

Almost surely, 2^813973957 is an apocalyptic number.

It is an amenable number.

813973957 is a deficient number, since it is larger than the sum of its proper divisors (47880839).

813973957 is a wasteful number, since it uses less digits than its factorization.

813973957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47880838.

The product of its digits is 1428840, while the sum is 52.

The square root of 813973957 is about 28530.2288283848. The cubic root of 813973957 is about 933.6917109992.

The spelling of 813973957 in words is "eight hundred thirteen million, nine hundred seventy-three thousand, nine hundred fifty-seven".