101009591 has 4 divisors (see below), whose sum is σ = 101244384. Its totient is φ = 100774800.

The previous prime is 101009551. The next prime is 101009603. The reversal of 101009591 is 195900101.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 195900101 = 181 ⋅1082321.

It is a cyclic number.

It is not a de Polignac number, because 101009591 - 2¹⁸ = 100747447 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 101009591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101009551) 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, 116750 + ... + 117611.

It is an arithmetic number, because the mean of its divisors is an integer number (25311096).

Almost surely, 2^101009591 is an apocalyptic number.

101009591 is a deficient number, since it is larger than the sum of its proper divisors (234793).

101009591 is an equidigital number, since it uses as much as digits as its factorization.

101009591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234792.

The product of its (nonzero) digits is 405, while the sum is 26.

The square root of 101009591 is about 10050.3527798779. The cubic root of 101009591 is about 465.7156913627.

Adding to 101009591 its reverse (195900101), we get a palindrome (296909692).

It can be divided in two parts, 10100 and 9591, that added together give a palindrome (19691).

The spelling of 101009591 in words is "one hundred one million, nine thousand, five hundred ninety-one".