213042781 has 16 divisors (see below), whose sum is σ = 253810816. Its totient is φ = 175006656.

The previous prime is 213042701. The next prime is 213042803. The reversal of 213042781 is 187240312.

It is a cyclic number.

It is not a de Polignac number, because 213042781 - 2¹⁵ = 213010013 is a prime.

It is a super-2 number, since 2×213042781² = 90774453072427922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213042701) 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, 11215 + ... + 23491.

It is an arithmetic number, because the mean of its divisors is an integer number (15863176).

Almost surely, 2^213042781 is an apocalyptic number.

It is an amenable number.

213042781 is a deficient number, since it is larger than the sum of its proper divisors (40768035).

213042781 is a wasteful number, since it uses less digits than its factorization.

213042781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12388.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 213042781 is about 14595.9850986496. The cubic root of 213042781 is about 597.2492424194.

The spelling of 213042781 in words is "two hundred thirteen million, forty-two thousand, seven hundred eighty-one".