61572222121 has 2 divisors, whose sum is σ = 61572222122. Its totient is φ = 61572222120.

The previous prime is 61572222091. The next prime is 61572222133. The reversal of 61572222121 is 12122227516.

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., 48152158096 + 13420064025 = 219436^2 + 115845^2 .

It is a cyclic number.

It is not a de Polignac number, because 61572222121 - 2⁷ = 61572221993 is a prime.

It is a super-2 number, since 2×61572222121² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61572220121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30786111060 + 30786111061.

It is an arithmetic number, because the mean of its divisors is an integer number (30786111061).

Almost surely, 2^61572222121 is an apocalyptic number.

It is an amenable number.

61572222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

61572222121 is an equidigital number, since it uses as much as digits as its factorization.

61572222121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 31.

Adding to 61572222121 its reverse (12122227516), we get a palindrome (73694449637).

The spelling of 61572222121 in words is "sixty-one billion, five hundred seventy-two million, two hundred twenty-two thousand, one hundred twenty-one".