90450091 has 4 divisors (see below), whose sum is σ = 90660384. Its totient is φ = 90239800.

The previous prime is 90450083. The next prime is 90450103. The reversal of 90450091 is 19005409.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19005409 = 1231 ⋅15439.

It is a cyclic number.

It is not a de Polignac number, because 90450091 - 2³ = 90450083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90450071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104500 + ... + 105361.

It is an arithmetic number, because the mean of its divisors is an integer number (22665096).

Almost surely, 2^90450091 is an apocalyptic number.

90450091 is a deficient number, since it is larger than the sum of its proper divisors (210293).

90450091 is a wasteful number, since it uses less digits than its factorization.

90450091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210292.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 90450091 is about 9510.5252746628. The cubic root of 90450091 is about 448.8862845971.

The spelling of 90450091 in words is "ninety million, four hundred fifty thousand, ninety-one".