213021740 has 24 divisors (see below), whose sum is σ = 450314592. Its totient is φ = 84643200.

The previous prime is 213021707. The next prime is 213021803. The reversal of 213021740 is 47120312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32249 + ... + 38288.

It is an arithmetic number, because the mean of its divisors is an integer number (18763108).

Almost surely, 2^213021740 is an apocalyptic number.

213021740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213021740 is an abundant number, since it is smaller than the sum of its proper divisors (237292852).

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

213021740 is a wasteful number, since it uses less digits than its factorization.

213021740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70697 (or 70695 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 213021740 is about 14595.2643004503. The cubic root of 213021740 is about 597.2295794907.

The spelling of 213021740 in words is "two hundred thirteen million, twenty-one thousand, seven hundred forty".