213157261 has 4 divisors (see below), whose sum is σ = 222424992. Its totient is φ = 203889532.

The previous prime is 213157253. The next prime is 213157283. The reversal of 213157261 is 162751312.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 213157261 - 2³ = 213157253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213157201) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 4633831 + ... + 4633876.

It is an arithmetic number, because the mean of its divisors is an integer number (55606248).

Almost surely, 2^213157261 is an apocalyptic number.

It is an amenable number.

213157261 is a deficient number, since it is larger than the sum of its proper divisors (9267731).

213157261 is an equidigital number, since it uses as much as digits as its factorization.

213157261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9267730.

The product of its digits is 2520, while the sum is 28.

The square root of 213157261 is about 14599.9061983288. The cubic root of 213157261 is about 597.3562019226.

The spelling of 213157261 in words is "two hundred thirteen million, one hundred fifty-seven thousand, two hundred sixty-one".