890991551 has 2 divisors, whose sum is σ = 890991552. Its totient is φ = 890991550.

The previous prime is 890991523. The next prime is 890991557. The reversal of 890991551 is 155199098.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 890991551 - 2¹⁸ = 890729407 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 890991496 and 890991505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (890991557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445495775 + 445495776.

It is an arithmetic number, because the mean of its divisors is an integer number (445495776).

Almost surely, 2^890991551 is an apocalyptic number.

890991551 is a deficient number, since it is larger than the sum of its proper divisors (1).

890991551 is an equidigital number, since it uses as much as digits as its factorization.

890991551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145800, while the sum is 47.

The square root of 890991551 is about 29849.4815867881. The cubic root of 890991551 is about 962.2572574114.

The spelling of 890991551 in words is "eight hundred ninety million, nine hundred ninety-one thousand, five hundred fifty-one".