213898921 has 2 divisors, whose sum is σ = 213898922. Its totient is φ = 213898920.

The previous prime is 213898897. The next prime is 213898963. The reversal of 213898921 is 129898312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199911321 + 13987600 = 14139^2 + 3740^2 .

It is a cyclic number.

It is not a de Polignac number, because 213898921 - 2⁷ = 213898793 is a prime.

It is not a weakly prime, because it can be changed into another prime (213898121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106949460 + 106949461.

It is an arithmetic number, because the mean of its divisors is an integer number (106949461).

Almost surely, 2^213898921 is an apocalyptic number.

It is an amenable number.

213898921 is a deficient number, since it is larger than the sum of its proper divisors (1).

213898921 is an equidigital number, since it uses as much as digits as its factorization.

213898921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 43.

The square root of 213898921 is about 14625.2836211815. The cubic root of 213898921 is about 598.0482142533.

The spelling of 213898921 in words is "two hundred thirteen million, eight hundred ninety-eight thousand, nine hundred twenty-one".