811961653 has 4 divisors (see below), whose sum is σ = 812326860. Its totient is φ = 811596448.

The previous prime is 811961629. The next prime is 811961659. The reversal of 811961653 is 356169118.

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 619362769 + 192598884 = 24887^2 + 13878^2 .

It is a cyclic number.

It is not a de Polignac number, because 811961653 - 2⁵ = 811961621 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 (811961659) 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, 179248 + ... + 183721.

It is an arithmetic number, because the mean of its divisors is an integer number (203081715).

Almost surely, 2^811961653 is an apocalyptic number.

It is an amenable number.

811961653 is a deficient number, since it is larger than the sum of its proper divisors (365207).

811961653 is a wasteful number, since it uses less digits than its factorization.

811961653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365206.

The product of its digits is 38880, while the sum is 40.

The square root of 811961653 is about 28494.9408316634. The cubic root of 811961653 is about 932.9216527796.

The spelling of 811961653 in words is "eight hundred eleven million, nine hundred sixty-one thousand, six hundred fifty-three".