99990001 has 2 divisors, whose sum is σ = 99990002. Its totient is φ = 99990000.

The previous prime is 99989983. The next prime is 99990029. The reversal of 99990001 is 10009999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99980001 + 10000 = 9999^2 + 100^2 .

It is a cyclic number.

It is not a de Polignac number, because 99990001 - 2⁹ = 99989489 is a prime.

It is the 10000-th Hogben number.

It is not a weakly prime, because it can be changed into another prime (99990091) by changing a digit.

It is a nontrivial repunit in base 9999.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49995000 + 49995001.

It is an arithmetic number, because the mean of its divisors is an integer number (49995001).

Almost surely, 2^99990001 is an apocalyptic number.

It is an amenable number.

99990001 is a deficient number, since it is larger than the sum of its proper divisors (1).

99990001 is an equidigital number, since it uses as much as digits as its factorization.

99990001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6561, while the sum is 37.

The square root of 99990001 is about 9999.5000375019. The cubic root of 99990001 is about 464.1434124300.

The spelling of 99990001 in words is "ninety-nine million, nine hundred ninety thousand, one".