90751 has 4 divisors (see below), whose sum is σ = 91504. Its totient is φ = 90000.

The previous prime is 90749. The next prime is 90787. The reversal of 90751 is 15709.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 15709 = 23 ⋅683.

It is a 4-Lehmer number, since φ(90751) divides (90751-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 90751 - 2¹ = 90749 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 150 + ... + 451.

It is an arithmetic number, because the mean of its divisors is an integer number (22876).

It is a Poulet number, since it divides 2⁹⁰⁷⁵⁰-1.

2⁹⁰⁷⁵¹ is an apocalyptic number.

90751 is the 151-st decagonal number.

90751 is a deficient number, since it is larger than the sum of its proper divisors (753).

90751 is a wasteful number, since it uses less digits than its factorization.

90751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752.

The product of its (nonzero) digits is 315, while the sum is 22.

The square root of 90751 is about 301.2490663886. The cubic root of 90751 is about 44.9383517970.

It can be divided in two parts, 90 and 751, that added together give a square (841 = 29²).

The spelling of 90751 in words is "ninety thousand, seven hundred fifty-one".