202123021091 has 2 divisors, whose sum is σ = 202123021092. Its totient is φ = 202123021090.

The previous prime is 202123020971. The next prime is 202123021099. The reversal of 202123021091 is 190120321202.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 202123021091 - 2³⁰ = 201049279267 is a prime.

It is not a weakly prime, because it can be changed into another prime (202123021099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101061510545 + 101061510546.

It is an arithmetic number, because the mean of its divisors is an integer number (101061510546).

Almost surely, 2^202123021091 is an apocalyptic number.

202123021091 is a deficient number, since it is larger than the sum of its proper divisors (1).

202123021091 is an equidigital number, since it uses as much as digits as its factorization.

202123021091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 202123021091 its reverse (190120321202), we get a palindrome (392243342293).

The spelling of 202123021091 in words is "two hundred two billion, one hundred twenty-three million, twenty-one thousand, ninety-one".