1021421255201 has 16 divisors (see below), whose sum is σ = 1049029347408. Its totient is φ = 994166784000.

The previous prime is 1021421255191. The next prime is 1021421255209. The reversal of 1021421255201 is 1025521241201.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 33544288801 + 987876966400 = 183151^2 + 993920^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021421255201 - 2⁶ = 1021421255137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021421255209) 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, 69227441 + ... + 69242193.

It is an arithmetic number, because the mean of its divisors is an integer number (65564334213).

Almost surely, 2^{1021421255201} is an apocalyptic number.

It is an amenable number.

1021421255201 is a deficient number, since it is larger than the sum of its proper divisors (27608092207).

1021421255201 is a wasteful number, since it uses less digits than its factorization.

1021421255201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26612.

The product of its (nonzero) digits is 1600, while the sum is 26.

Adding to 1021421255201 its reverse (1025521241201), we get a palindrome (2046942496402).

The spelling of 1021421255201 in words is "one trillion, twenty-one billion, four hundred twenty-one million, two hundred fifty-five thousand, two hundred one".