90728243857 has 32 divisors (see below), whose sum is σ = 101047564800. Its totient is φ = 81070080000.

The previous prime is 90728243839. The next prime is 90728243861. The reversal of 90728243857 is 75834282709.

It is a happy number.

It is not a de Polignac number, because 90728243857 - 2⁷ = 90728243729 is a prime.

It is a super-2 number, since 2×90728243857² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 90728243798 and 90728243807.

It is not an unprimeable number, because it can be changed into a prime (90728243897) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9771057 + ... + 9780337.

It is an arithmetic number, because the mean of its divisors is an integer number (3157736400).

Almost surely, 2^90728243857 is an apocalyptic number.

It is an amenable number.

90728243857 is a deficient number, since it is larger than the sum of its proper divisors (10319320943).

90728243857 is a wasteful number, since it uses less digits than its factorization.

90728243857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9657.

The product of its (nonzero) digits is 6773760, while the sum is 55.

The spelling of 90728243857 in words is "ninety billion, seven hundred twenty-eight million, two hundred forty-three thousand, eight hundred fifty-seven".