210993090 has 128 divisors (see below), whose sum is σ = 635627520. Its totient is φ = 43545600.

The previous prime is 210993077. The next prime is 210993091. The reversal of 210993090 is 90399012.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (210993091) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 556521 + ... + 556899.

It is an arithmetic number, because the mean of its divisors is an integer number (4965840).

Almost surely, 2^210993090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 210993090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (317813760).

210993090 is an abundant number, since it is smaller than the sum of its proper divisors (424634430).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

210993090 is a wasteful number, since it uses less digits than its factorization.

210993090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 210993090 is about 14525.6011923775. The cubic root of 210993090 is about 595.3276824133.

The spelling of 210993090 in words is "two hundred ten million, nine hundred ninety-three thousand, ninety".