101811381 has 16 divisors (see below), whose sum is σ = 155295744. Its totient is φ = 58119984.

The previous prime is 101811377. The next prime is 101811397. The reversal of 101811381 is 183118101.

It is not a de Polignac number, because 101811381 - 2² = 101811377 is a prime.

It is a super-2 number, since 2×101811381² = 20731114602254322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101811301) 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 15 ways as a sum of consecutive naturals, for example, 28180 + ... + 31586.

It is an arithmetic number, because the mean of its divisors is an integer number (9705984).

Almost surely, 2^101811381 is an apocalyptic number.

It is an amenable number.

101811381 is a deficient number, since it is larger than the sum of its proper divisors (53484363).

101811381 is a wasteful number, since it uses less digits than its factorization.

101811381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4840.

The product of its (nonzero) digits is 192, while the sum is 24.

The square root of 101811381 is about 10090.1625854096. The cubic root of 101811381 is about 466.9446918682.

Adding to 101811381 its reverse (183118101), we get a palindrome (284929482).

The spelling of 101811381 in words is "one hundred one million, eight hundred eleven thousand, three hundred eighty-one".