1021200123021 has 16 divisors (see below), whose sum is σ = 1468355650944. Its totient is φ = 627566410944.

The previous prime is 1021200123017. The next prime is 1021200123023. The reversal of 1021200123021 is 1203210021201.

It is not a de Polignac number, because 1021200123021 - 2² = 1021200123017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021200123023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17980326 + ... + 18037031.

It is an arithmetic number, because the mean of its divisors is an integer number (91772228184).

Almost surely, 2^{1021200123021} is an apocalyptic number.

It is an amenable number.

1021200123021 is a deficient number, since it is larger than the sum of its proper divisors (447155527923).

1021200123021 is a wasteful number, since it uses less digits than its factorization.

1021200123021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36018100.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 1021200123021 its reverse (1203210021201), we get a palindrome (2224410144222).

The spelling of 1021200123021 in words is "one trillion, twenty-one billion, two hundred million, one hundred twenty-three thousand, twenty-one".