90001209 has 16 divisors (see below), whose sum is σ = 121201344. Its totient is φ = 59404800.

The previous prime is 90001207. The next prime is 90001211. The reversal of 90001209 is 90210009.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (90001207) and next prime (90001211).

It is not a de Polignac number, because 90001209 - 2¹ = 90001207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90001207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 202942 + ... + 203384.

It is an arithmetic number, because the mean of its divisors is an integer number (7575084).

Almost surely, 2^90001209 is an apocalyptic number.

It is an amenable number.

90001209 is a deficient number, since it is larger than the sum of its proper divisors (31200135).

90001209 is a wasteful number, since it uses less digits than its factorization.

90001209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968.

The product of its (nonzero) digits is 162, while the sum is 21.

The square root of 90001209 is about 9486.8967001860. The cubic root of 90001209 is about 448.1424813202.

The spelling of 90001209 in words is "ninety million, one thousand, two hundred nine".