1200023021 has 2 divisors, whose sum is σ = 1200023022. Its totient is φ = 1200023020.

The previous prime is 1200023017. The next prime is 1200023023. The reversal of 1200023021 is 1203200021.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 658948900 + 541074121 = 25670^2 + 23261^2 .

It is a cyclic number.

It is not a de Polignac number, because 1200023021 - 2² = 1200023017 is a prime.

Together with 1200023023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1200022993 and 1200023011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1200023023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600011510 + 600011511.

It is an arithmetic number, because the mean of its divisors is an integer number (600011511).

Almost surely, 2^1200023021 is an apocalyptic number.

It is an amenable number.

1200023021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200023021 is an equidigital number, since it uses as much as digits as its factorization.

1200023021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 1200023021 is about 34641.3484292976. The cubic root of 1200023021 is about 1062.6653645455.

Adding to 1200023021 its reverse (1203200021), we get a palindrome (2403223042).

The spelling of 1200023021 in words is "one billion, two hundred million, twenty-three thousand, twenty-one".