249628021 has 4 divisors (see below), whose sum is σ = 249665344. Its totient is φ = 249590700.

The previous prime is 249628013. The next prime is 249628033. The reversal of 249628021 is 120826942.

249628021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 249628021 - 2³ = 249628013 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 (249628081) 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, 5565 + ... + 23026.

It is an arithmetic number, because the mean of its divisors is an integer number (62416336).

Almost surely, 2^249628021 is an apocalyptic number.

It is an amenable number.

249628021 is a deficient number, since it is larger than the sum of its proper divisors (37323).

249628021 is an equidigital number, since it uses as much as digits as its factorization.

249628021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37322.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 249628021 is about 15799.6209131738. The cubic root of 249628021 is about 629.6479270749.

The spelling of 249628021 in words is "two hundred forty-nine million, six hundred twenty-eight thousand, twenty-one".