90991278 has 24 divisors (see below), whose sum is σ = 225312048. Its totient is φ = 25997472.

The previous prime is 90991273. The next prime is 90991279. The reversal of 90991278 is 87219909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90991273) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 360951 + ... + 361202.

It is an arithmetic number, because the mean of its divisors is an integer number (9388002).

Almost surely, 2^90991278 is an apocalyptic number.

90991278 is an abundant number, since it is smaller than the sum of its proper divisors (134320770).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

90991278 is a wasteful number, since it uses less digits than its factorization.

90991278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722168 (or 722165 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 90991278 is about 9538.9348461975. The cubic root of 90991278 is about 449.7797737221.

The spelling of 90991278 in words is "ninety million, nine hundred ninety-one thousand, two hundred seventy-eight".