899724821 has 8 divisors (see below), whose sum is σ = 904573440. Its totient is φ = 894885712.

The previous prime is 899724809. The next prime is 899724829. The reversal of 899724821 is 128427998.

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 899724821 - 2⁶ = 899724757 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 899724821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (899724829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261911 + ... + 265323.

It is an arithmetic number, because the mean of its divisors is an integer number (113071680).

Almost surely, 2^899724821 is an apocalyptic number.

It is an amenable number.

899724821 is a deficient number, since it is larger than the sum of its proper divisors (4848619).

899724821 is a wasteful number, since it uses less digits than its factorization.

899724821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4755.

The product of its digits is 580608, while the sum is 50.

The square root of 899724821 is about 29995.4133327081. The cubic root of 899724821 is about 965.3909736850.

The spelling of 899724821 in words is "eight hundred ninety-nine million, seven hundred twenty-four thousand, eight hundred twenty-one".