1572342221 has 2 divisors, whose sum is σ = 1572342222. Its totient is φ = 1572342220.

The previous prime is 1572342203. The next prime is 1572342319. The reversal of 1572342221 is 1222432751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1551966025 + 20376196 = 39395^2 + 4514^2 .

It is a cyclic number.

It is not a de Polignac number, because 1572342221 - 2⁶ = 1572342157 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1572362221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 786171110 + 786171111.

It is an arithmetic number, because the mean of its divisors is an integer number (786171111).

Almost surely, 2^1572342221 is an apocalyptic number.

It is an amenable number.

1572342221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1572342221 is an equidigital number, since it uses as much as digits as its factorization.

1572342221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 29.

The square root of 1572342221 is about 39652.7706598164. The cubic root of 1572342221 is about 1162.8285661002.

Adding to 1572342221 its reverse (1222432751), we get a palindrome (2794774972).

The spelling of 1572342221 in words is "one billion, five hundred seventy-two million, three hundred forty-two thousand, two hundred twenty-one".