210100100121 has 12 divisors (see below), whose sum is σ = 303494081748. Its totient is φ = 140059275264.

The previous prime is 210100100117. The next prime is 210100100137. The reversal of 210100100121 is 121001001012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 35848120896 + 174251979225 = 189336^2 + 417435^2 .

It is not a de Polignac number, because 210100100121 - 2² = 210100100117 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (210100100141) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 440320 + ... + 783633.

It is an arithmetic number, because the mean of its divisors is an integer number (25291173479).

Almost surely, 2^210100100121 is an apocalyptic number.

It is an amenable number.

210100100121 is a deficient number, since it is larger than the sum of its proper divisors (93393981627).

210100100121 is a wasteful number, since it uses less digits than its factorization.

210100100121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1243032 (or 1243029 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 210100100121 its reverse (121001001012), we get a palindrome (331101101133).

The spelling of 210100100121 in words is "two hundred ten billion, one hundred million, one hundred thousand, one hundred twenty-one".