891690361 has 2 divisors, whose sum is σ = 891690362. Its totient is φ = 891690360.

The previous prime is 891690353. The next prime is 891690367. The reversal of 891690361 is 163096198.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 583512336 + 308178025 = 24156^2 + 17555^2 .

It is a cyclic number.

It is not a de Polignac number, because 891690361 - 2³ = 891690353 is a prime.

It is a super-2 number, since 2×891690361² = 1590223399800620642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (891690367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445845180 + 445845181.

It is an arithmetic number, because the mean of its divisors is an integer number (445845181).

Almost surely, 2^891690361 is an apocalyptic number.

It is an amenable number.

891690361 is a deficient number, since it is larger than the sum of its proper divisors (1).

891690361 is an equidigital number, since it uses as much as digits as its factorization.

891690361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 891690361 is about 29861.1848559296. The cubic root of 891690361 is about 962.5087597111.

The spelling of 891690361 in words is "eight hundred ninety-one million, six hundred ninety thousand, three hundred sixty-one".