101919981 has 8 divisors (see below), whose sum is σ = 143887104. Its totient is φ = 63949760.

The previous prime is 101919967. The next prime is 101919989. The reversal of 101919981 is 189919101.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 101919981 - 2¹⁸ = 101657837 is a prime.

It is a super-2 number, since 2×101919981² = 20775365054080722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (101919989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 999165 + ... + 999266.

It is an arithmetic number, because the mean of its divisors is an integer number (17985888).

Almost surely, 2^101919981 is an apocalyptic number.

It is an amenable number.

101919981 is a deficient number, since it is larger than the sum of its proper divisors (41967123).

101919981 is a wasteful number, since it uses less digits than its factorization.

101919981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1998451.

The product of its (nonzero) digits is 5832, while the sum is 39.

The square root of 101919981 is about 10095.5426302899. The cubic root of 101919981 is about 467.1106594749.

The spelling of 101919981 in words is "one hundred one million, nine hundred nineteen thousand, nine hundred eighty-one".