70890509 has 4 divisors (see below), whose sum is σ = 70918620. Its totient is φ = 70862400.

The previous prime is 70890503. The next prime is 70890551. The reversal of 70890509 is 90509807.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39564100 + 31326409 = 6290^2 + 5597^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70890509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70890503) 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, 9854 + ... + 15455.

It is an arithmetic number, because the mean of its divisors is an integer number (17729655).

Almost surely, 2^70890509 is an apocalyptic number.

It is an amenable number.

70890509 is a deficient number, since it is larger than the sum of its proper divisors (28111).

70890509 is a wasteful number, since it uses less digits than its factorization.

70890509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28110.

The product of its (nonzero) digits is 22680, while the sum is 38.

The square root of 70890509 is about 8419.6501708800. The cubic root of 70890509 is about 413.8688099030.

The spelling of 70890509 in words is "seventy million, eight hundred ninety thousand, five hundred nine".