994131581 has 2 divisors, whose sum is σ = 994131582. Its totient is φ = 994131580.

The previous prime is 994131539. The next prime is 994131643. The reversal of 994131581 is 185131499.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 720063556 + 274068025 = 26834^2 + 16555^2 .

It is a cyclic number.

It is not a de Polignac number, because 994131581 - 2⁶ = 994131517 is a prime.

It is a super-2 number, since 2×994131581² = 1976595200683119122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (994130581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 497065790 + 497065791.

It is an arithmetic number, because the mean of its divisors is an integer number (497065791).

Almost surely, 2^994131581 is an apocalyptic number.

It is an amenable number.

994131581 is a deficient number, since it is larger than the sum of its proper divisors (1).

994131581 is an equidigital number, since it uses as much as digits as its factorization.

994131581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 41.

The square root of 994131581 is about 31529.8522197615. The cubic root of 994131581 is about 998.0400213267.

The spelling of 994131581 in words is "nine hundred ninety-four million, one hundred thirty-one thousand, five hundred eighty-one".