10121001021 has 6 divisors (see below), whose sum is σ = 14619223710. Its totient is φ = 6747334008.

The previous prime is 10121001013. The next prime is 10121001061. The reversal of 10121001021 is 12010012101.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 8290102500 + 1830898521 = 91050^2 + 42789^2 .

It is not a de Polignac number, because 10121001021 - 2³ = 10121001013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 1124555669 = 10121001021 / (1 + 0 + 1 + 2 + 1 + 0 + 0 + 1 + 0 + 2 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 10121000994 and 10121001012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10121001001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 562277826 + ... + 562277843.

It is an arithmetic number, because the mean of its divisors is an integer number (2436537285).

Almost surely, 2^10121001021 is an apocalyptic number.

It is an amenable number.

10121001021 is a deficient number, since it is larger than the sum of its proper divisors (4498222689).

10121001021 is a wasteful number, since it uses less digits than its factorization.

10121001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1124555675 (or 1124555672 counting only the distinct ones).

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

Adding to 10121001021 its reverse (12010012101), we get a palindrome (22131013122).

The spelling of 10121001021 in words is "ten billion, one hundred twenty-one million, one thousand, twenty-one".