102120012100021 has 4 divisors (see below), whose sum is σ = 102257454916512. Its totient is φ = 101982569283532.

The previous prime is 102120012099991. The next prime is 102120012100033. The reversal of 102120012100021 is 120001210021201.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 102120012100021 - 2¹³ = 102120012091829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 102120012099974 and 102120012100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102120012100121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68721407131 + ... + 68721408616.

It is an arithmetic number, because the mean of its divisors is an integer number (25564363729128).

Almost surely, 2^{102120012100021} is an apocalyptic number.

It is an amenable number.

102120012100021 is a deficient number, since it is larger than the sum of its proper divisors (137442816491).

102120012100021 is an equidigital number, since it uses as much as digits as its factorization.

102120012100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137442816490.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 102120012100021 its reverse (120001210021201), we get a palindrome (222121222121222).

The spelling of 102120012100021 in words is "one hundred two trillion, one hundred twenty billion, twelve million, one hundred thousand, twenty-one".