210131993 has 2 divisors, whose sum is σ = 210131994. Its totient is φ = 210131992.

The previous prime is 210131989. The next prime is 210132017. The reversal of 210131993 is 399131012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115498009 + 94633984 = 10747^2 + 9728^2 .

It is a cyclic number.

It is not a de Polignac number, because 210131993 - 2² = 210131989 is a prime.

It is a Chen prime.

It is equal to p_11608463 and since 210131993 and 11608463 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (210131903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105065996 + 105065997.

It is an arithmetic number, because the mean of its divisors is an integer number (105065997).

Almost surely, 2^210131993 is an apocalyptic number.

It is an amenable number.

210131993 is a deficient number, since it is larger than the sum of its proper divisors (1).

210131993 is an equidigital number, since it uses as much as digits as its factorization.

210131993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 210131993 is about 14495.9302219623. The cubic root of 210131993 is about 594.5167019070.

The spelling of 210131993 in words is "two hundred ten million, one hundred thirty-one thousand, nine hundred ninety-three".