90212729 has 4 divisors (see below), whose sum is σ = 90309540. Its totient is φ = 90115920.

The previous prime is 90212723. The next prime is 90212737. The reversal of 90212729 is 92721209.

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 35378704 + 54834025 = 5948^2 + 7405^2 .

It is a cyclic number.

It is not a de Polignac number, because 90212729 - 2¹⁶ = 90147193 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90212695 and 90212704.

It is not an unprimeable number, because it can be changed into a prime (90212723) 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, 46994 + ... + 48875.

It is an arithmetic number, because the mean of its divisors is an integer number (22577385).

Almost surely, 2^90212729 is an apocalyptic number.

It is an amenable number.

90212729 is a deficient number, since it is larger than the sum of its proper divisors (96811).

90212729 is an equidigital number, since it uses as much as digits as its factorization.

90212729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96810.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 90212729 is about 9498.0381658530. The cubic root of 90212729 is about 448.4932800723.

It can be divided in two parts, 902 and 12729, that added together give a palindrome (13631).

The spelling of 90212729 in words is "ninety million, two hundred twelve thousand, seven hundred twenty-nine".