61131021421 has 2 divisors, whose sum is σ = 61131021422. Its totient is φ = 61131021420.

The previous prime is 61131021407. The next prime is 61131021433. The reversal of 61131021421 is 12412013116.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52381476900 + 8749544521 = 228870^2 + 93539^2 .

It is a cyclic number.

It is not a de Polignac number, because 61131021421 - 2¹⁷ = 61130890349 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61131021392 and 61131021401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61131021451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30565510710 + 30565510711.

It is an arithmetic number, because the mean of its divisors is an integer number (30565510711).

Almost surely, 2^61131021421 is an apocalyptic number.

It is an amenable number.

61131021421 is a deficient number, since it is larger than the sum of its proper divisors (1).

61131021421 is an equidigital number, since it uses as much as digits as its factorization.

61131021421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 61131021421 its reverse (12412013116), we get a palindrome (73543034537).

The spelling of 61131021421 in words is "sixty-one billion, one hundred thirty-one million, twenty-one thousand, four hundred twenty-one".