213231881 has 2 divisors, whose sum is σ = 213231882. Its totient is φ = 213231880.

The previous prime is 213231877. The next prime is 213231911. The reversal of 213231881 is 188132312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192071881 + 21160000 = 13859^2 + 4600^2 .

It is a cyclic number.

It is not a de Polignac number, because 213231881 - 2² = 213231877 is a prime.

It is a super-2 number, since 2×213231881² = 90935670149596322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (213231181) 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 as a sum of consecutive naturals, namely, 106615940 + 106615941.

It is an arithmetic number, because the mean of its divisors is an integer number (106615941).

Almost surely, 2^213231881 is an apocalyptic number.

It is an amenable number.

213231881 is a deficient number, since it is larger than the sum of its proper divisors (1).

213231881 is an equidigital number, since it uses as much as digits as its factorization.

213231881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 29.

The square root of 213231881 is about 14602.4614705878. The cubic root of 213231881 is about 597.4258993206.

The spelling of 213231881 in words is "two hundred thirteen million, two hundred thirty-one thousand, eight hundred eighty-one".