865006921 has 3 divisors (see below), whose sum is σ = 865036333. Its totient is φ = 864977510.

The previous prime is 865006897. The next prime is 865006927. The reversal of 865006921 is 129600568.

The square root of 865006921 is 29411.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 865006921 - 2²³ = 856618313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (865006927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 14706 + ... + 44116.

Almost surely, 2^865006921 is an apocalyptic number.

865006921 is the 29411-st square number.

865006921 is the 14706-th centered octagonal number.

It is an amenable number.

865006921 is a deficient number, since it is larger than the sum of its proper divisors (29412).

865006921 is an frugal number, since it uses more digits than its factorization.

865006921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58822 (or 29411 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The cubic root of 865006921 is about 952.8104846362.

The spelling of 865006921 in words is "eight hundred sixty-five million, six thousand, nine hundred twenty-one".