100021020121 has 9 divisors (see below), whose sum is σ = 109944284149. Its totient is φ = 90925037500.

The previous prime is 100021020109. The next prime is 100021020131. The reversal of 100021020121 is 121020120001.

The square root of 100021020121 is 316261.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 100021020121 - 2¹¹ = 100021018073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100021020098 and 100021020107.

It is not an unprimeable number, because it can be changed into a prime (100021020131) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3464496 + ... + 3493246.

Almost surely, 2^100021020121 is an apocalyptic number.

100021020121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

100021020121 is the 316261-st square number.

100021020121 is the 158131-st centered octagonal number.

It is an amenable number.

100021020121 is a deficient number, since it is larger than the sum of its proper divisors (9923264028).

100021020121 is an frugal number, since it uses more digits than its factorization.

100021020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57524 (or 28762 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 100021020121 its reverse (121020120001), we get a palindrome (221041140122).

The spelling of 100021020121 in words is "one hundred billion, twenty-one million, twenty thousand, one hundred twenty-one".