91251001 has 4 divisors (see below), whose sum is σ = 92972772. Its totient is φ = 89529232.

The previous prime is 91250989. The next prime is 91251029. The reversal of 91251001 is 10015219.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10015219 = 967 ⋅10357.

It can be written as a sum of positive squares in 2 ways, for example, as 67980025 + 23270976 = 8245^2 + 4824^2 .

It is a cyclic number.

It is not a de Polignac number, because 91251001 - 2¹⁷ = 91119929 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91251001.

It is not an unprimeable number, because it can be changed into a prime (91254001) 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, 860806 + ... + 860911.

It is an arithmetic number, because the mean of its divisors is an integer number (23243193).

Almost surely, 2^91251001 is an apocalyptic number.

It is an amenable number.

91251001 is a deficient number, since it is larger than the sum of its proper divisors (1721771).

91251001 is a wasteful number, since it uses less digits than its factorization.

91251001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1721770.

The product of its (nonzero) digits is 90, while the sum is 19.

The square root of 91251001 is about 9552.5389818624. The cubic root of 91251001 is about 450.2073135302.

The spelling of 91251001 in words is "ninety-one million, two hundred fifty-one thousand, one".