9990551 has 2 divisors, whose sum is σ = 9990552. Its totient is φ = 9990550.

The previous prime is 9990499. The next prime is 9990557. The reversal of 9990551 is 1550999.

9990551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (1550999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9990551 - 2²² = 5796247 is a prime.

It is a super-2 number, since 2×9990551² = 199622218567202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9990557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995275 + 4995276.

It is an arithmetic number, because the mean of its divisors is an integer number (4995276).

Almost surely, 2^9990551 is an apocalyptic number.

9990551 is a deficient number, since it is larger than the sum of its proper divisors (1).

9990551 is an equidigital number, since it uses as much as digits as its factorization.

9990551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18225, while the sum is 38.

The square root of 9990551 is about 3160.7832889966. The cubic root of 9990551 is about 215.3755901078.

The spelling of 9990551 in words is "nine million, nine hundred ninety thousand, five hundred fifty-one".