249999750021 has 16 divisors (see below), whose sum is σ = 380976195584. Its totient is φ = 142847926704.

The previous prime is 249999750019. The next prime is 249999750029. The reversal of 249999750021 is 120057999942.

249999750021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 249999750021 - 2¹ = 249999750019 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 (249999750029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32185 + ... + 707838.

It is an arithmetic number, because the mean of its divisors is an integer number (23811012224).

Almost surely, 2^249999750021 is an apocalyptic number.

249999750021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

249999750021 is a deficient number, since it is larger than the sum of its proper divisors (130976445563).

249999750021 is a wasteful number, since it uses less digits than its factorization.

249999750021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756120.

The product of its (nonzero) digits is 3674160, while the sum is 57.

The spelling of 249999750021 in words is "two hundred forty-nine billion, nine hundred ninety-nine million, seven hundred fifty thousand, twenty-one".