90987778 has 32 divisors (see below), whose sum is σ = 159252480. Its totient is φ = 38184720.

The previous prime is 90987749. The next prime is 90987781. The reversal of 90987778 is 87778909.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 237375 + ... + 237757.

It is an arithmetic number, because the mean of its divisors is an integer number (4976640).

Almost surely, 2^90987778 is an apocalyptic number.

90987778 is a deficient number, since it is larger than the sum of its proper divisors (68264702).

90987778 is a wasteful number, since it uses less digits than its factorization.

90987778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 702.

The product of its (nonzero) digits is 1778112, while the sum is 55.

The square root of 90987778 is about 9538.7513857947. The cubic root of 90987778 is about 449.7740066881.

The spelling of 90987778 in words is "ninety million, nine hundred eighty-seven thousand, seven hundred seventy-eight".