213057261 has 6 divisors (see below), whose sum is σ = 307749390. Its totient is φ = 142038168.

The previous prime is 213057259. The next prime is 213057269. The reversal of 213057261 is 162750312.

It is a happy number.

213057261 is a `hidden beast` number, since 2 + 1 + 30 + 572 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 182088036 + 30969225 = 13494^2 + 5565^2 .

It is not a de Polignac number, because 213057261 - 2¹ = 213057259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213057269) 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 5 ways as a sum of consecutive naturals, for example, 11836506 + ... + 11836523.

It is an arithmetic number, because the mean of its divisors is an integer number (51291565).

Almost surely, 2^213057261 is an apocalyptic number.

It is an amenable number.

213057261 is a deficient number, since it is larger than the sum of its proper divisors (94692129).

213057261 is a wasteful number, since it uses less digits than its factorization.

213057261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23673035 (or 23673032 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 213057261 is about 14596.4811170364. The cubic root of 213057261 is about 597.2627733060.

The spelling of 213057261 in words is "two hundred thirteen million, fifty-seven thousand, two hundred sixty-one".