90678509 has 4 divisors (see below), whose sum is σ = 91139004. Its totient is φ = 90218016.

The previous prime is 90678499. The next prime is 90678547. The reversal of 90678509 is 90587609.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90587609 = 7 ⋅12941087.

It can be written as a sum of positive squares in 2 ways, for example, as 66373609 + 24304900 = 8147^2 + 4930^2 .

It is a cyclic number.

It is not a de Polignac number, because 90678509 - 2⁸ = 90678253 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 90678509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90678109) 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, 229952 + ... + 230345.

It is an arithmetic number, because the mean of its divisors is an integer number (22784751).

Almost surely, 2^90678509 is an apocalyptic number.

It is an amenable number.

90678509 is a deficient number, since it is larger than the sum of its proper divisors (460495).

90678509 is a wasteful number, since it uses less digits than its factorization.

90678509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460494.

The product of its (nonzero) digits is 136080, while the sum is 44.

The square root of 90678509 is about 9522.5263979681. The cubic root of 90678509 is about 449.2638317283.

It can be divided in two parts, 9067 and 8509, that added together give a cube (17576 = 26³).

The spelling of 90678509 in words is "ninety million, six hundred seventy-eight thousand, five hundred nine".