890973781 has 2 divisors, whose sum is σ = 890973782. Its totient is φ = 890973780.

The previous prime is 890973773. The next prime is 890973799. The reversal of 890973781 is 187379098.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 518290756 + 372683025 = 22766^2 + 19305^2 .

It is a cyclic number.

It is not a de Polignac number, because 890973781 - 2³ = 890973773 is a prime.

It is a super-2 number, since 2×890973781² = 1587668556858871922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (890973761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445486890 + 445486891.

It is an arithmetic number, because the mean of its divisors is an integer number (445486891).

Almost surely, 2^890973781 is an apocalyptic number.

It is an amenable number.

890973781 is a deficient number, since it is larger than the sum of its proper divisors (1).

890973781 is an equidigital number, since it uses as much as digits as its factorization.

890973781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 762048, while the sum is 52.

The square root of 890973781 is about 29849.1839251930. The cubic root of 890973781 is about 962.2508602594.

The spelling of 890973781 in words is "eight hundred ninety million, nine hundred seventy-three thousand, seven hundred eighty-one".