90978729 has 4 divisors (see below), whose sum is σ = 121304976. Its totient is φ = 60652484.

The previous prime is 90978689. The next prime is 90978733. The reversal of 90978729 is 92787909.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90978729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90978029) 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, 15163119 + ... + 15163124.

It is an arithmetic number, because the mean of its divisors is an integer number (30326244).

Almost surely, 2^90978729 is an apocalyptic number.

It is an amenable number.

90978729 is a deficient number, since it is larger than the sum of its proper divisors (30326247).

90978729 is a wasteful number, since it uses less digits than its factorization.

90978729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30326246.

The product of its (nonzero) digits is 571536, while the sum is 51.

The square root of 90978729 is about 9538.2770456723. The cubic root of 90978729 is about 449.7590957480.

The spelling of 90978729 in words is "ninety million, nine hundred seventy-eight thousand, seven hundred twenty-nine".