101999854121 has 24 divisors (see below), whose sum is σ = 116028481800. Its totient is φ = 89493465600.

The previous prime is 101999854109. The next prime is 101999854189. The reversal of 101999854121 is 121458999101.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1107225625 + 100892628496 = 33275^2 + 317636^2 .

It is a de Polignac number, because none of the positive numbers 2^k-101999854121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 101999854121.

It is not an unprimeable number, because it can be changed into a prime (101999854321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12421265 + ... + 12429473.

It is an arithmetic number, because the mean of its divisors is an integer number (4834520075).

Almost surely, 2^101999854121 is an apocalyptic number.

101999854121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

101999854121 is a deficient number, since it is larger than the sum of its proper divisors (14028627679).

101999854121 is a wasteful number, since it uses less digits than its factorization.

101999854121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11801 (or 11790 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 50.

The spelling of 101999854121 in words is "one hundred one billion, nine hundred ninety-nine million, eight hundred fifty-four thousand, one hundred twenty-one".