90128739 has 8 divisors (see below), whose sum is σ = 120519360. Its totient is φ = 59911976.

The previous prime is 90128737. The next prime is 90128741. The reversal of 90128739 is 93782109.

It is an interprime number because it is at equal distance from previous prime (90128737) and next prime (90128741).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 90128739 - 2¹ = 90128737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 90128697 and 90128706.

It is not an unprimeable number, because it can be changed into a prime (90128737) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42249 + ... + 44330.

It is an arithmetic number, because the mean of its divisors is an integer number (15064920).

Almost surely, 2^90128739 is an apocalyptic number.

90128739 is a deficient number, since it is larger than the sum of its proper divisors (30390621).

90128739 is a wasteful number, since it uses less digits than its factorization.

90128739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86929.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 90128739 is about 9493.6156968776. The cubic root of 90128739 is about 448.3540512100.

The spelling of 90128739 in words is "ninety million, one hundred twenty-eight thousand, seven hundred thirty-nine".