210357021 has 16 divisors (see below), whose sum is σ = 320887424. Its totient is φ = 120075264.

The previous prime is 210357001. The next prime is 210357023. The reversal of 210357021 is 120753012.

210357021 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 210357021 - 2⁶ = 210356957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210357023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16845 + ... + 26541.

It is an arithmetic number, because the mean of its divisors is an integer number (20055464).

Almost surely, 2^210357021 is an apocalyptic number.

210357021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

210357021 is a deficient number, since it is larger than the sum of its proper divisors (110530403).

210357021 is a wasteful number, since it uses less digits than its factorization.

210357021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10740.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 210357021 is about 14503.6899098126. The cubic root of 210357021 is about 594.7288466251.

The spelling of 210357021 in words is "two hundred ten million, three hundred fifty-seven thousand, twenty-one".