90767981 has 8 divisors (see below), whose sum is σ = 97425144. Its totient is φ = 84257280.

The previous prime is 90767933. The next prime is 90767983. The reversal of 90767981 is 18976709.

It can be written as a sum of positive squares in 4 ways, for example, as 43626025 + 47141956 = 6605^2 + 6866^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 90767981 - 2¹⁴ = 90751597 is a prime.

It is a super-2 number, since 2×90767981² = 16477652749632722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90767983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35330 + ... + 37811.

It is an arithmetic number, because the mean of its divisors is an integer number (12178143).

Almost surely, 2^90767981 is an apocalyptic number.

It is an amenable number.

90767981 is a deficient number, since it is larger than the sum of its proper divisors (6657163).

90767981 is a wasteful number, since it uses less digits than its factorization.

90767981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73231.

The product of its (nonzero) digits is 190512, while the sum is 47.

The square root of 90767981 is about 9527.2231526295. The cubic root of 90767981 is about 449.4115452298.

The spelling of 90767981 in words is "ninety million, seven hundred sixty-seven thousand, nine hundred eighty-one".