90213989 has 4 divisors (see below), whose sum is σ = 90297324. Its totient is φ = 90130656.

The previous prime is 90213973. The next prime is 90214001. The reversal of 90213989 is 98931209.

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 63329764 + 26884225 = 7958^2 + 5185^2 .

It is a cyclic number.

It is not a de Polignac number, because 90213989 - 2⁴ = 90213973 is a prime.

It is a super-2 number, since 2×90213989² = 16277127622584242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90212989) 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, 40022 + ... + 42215.

It is an arithmetic number, because the mean of its divisors is an integer number (22574331).

Almost surely, 2^90213989 is an apocalyptic number.

It is an amenable number.

90213989 is a deficient number, since it is larger than the sum of its proper divisors (83335).

90213989 is a wasteful number, since it uses less digits than its factorization.

90213989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83334.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 90213989 is about 9498.1044951085. The cubic root of 90213989 is about 448.4953680958.

The spelling of 90213989 in words is "ninety million, two hundred thirteen thousand, nine hundred eighty-nine".