101551 has 4 divisors (see below), whose sum is σ = 102312. Its totient is φ = 100792.

The previous prime is 101537. The next prime is 101561. The reversal of 101551 is 155101.

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: 155101 = 43 ⋅3607.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-101551 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 (101501) 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, 121 + ... + 466.

It is an arithmetic number, because the mean of its divisors is an integer number (25578).

2¹⁰¹⁵⁵¹ is an apocalyptic number.

101551 is a deficient number, since it is larger than the sum of its proper divisors (761).

101551 is an equidigital number, since it uses as much as digits as its factorization.

101551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760.

The product of its (nonzero) digits is 25, while the sum is 13.

The square root of 101551 is about 318.6706764043. The cubic root of 101551 is about 46.6546284141.

Adding to 101551 its reverse (155101), we get a palindrome (256652).

The spelling of 101551 in words is "one hundred one thousand, five hundred fifty-one".