90399813 has 16 divisors (see below), whose sum is σ = 142196736. Its totient is φ = 49990320.

The previous prime is 90399809. The next prime is 90399839. The reversal of 90399813 is 31899309.

It is a happy number.

It is not a de Polignac number, because 90399813 - 2² = 90399809 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90399893) 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, 68781 + ... + 70082.

It is an arithmetic number, because the mean of its divisors is an integer number (8887296).

Almost surely, 2^90399813 is an apocalyptic number.

90399813 is a gapful number since it is divisible by the number (93) formed by its first and last digit.

It is an amenable number.

90399813 is a deficient number, since it is larger than the sum of its proper divisors (51796923).

90399813 is a wasteful number, since it uses less digits than its factorization.

90399813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138904.

The product of its (nonzero) digits is 52488, while the sum is 42.

The square root of 90399813 is about 9507.8816252623. The cubic root of 90399813 is about 448.8030958556.

The spelling of 90399813 in words is "ninety million, three hundred ninety-nine thousand, eight hundred thirteen".