61991273 has 2 divisors, whose sum is σ = 61991274. Its totient is φ = 61991272.

The previous prime is 61991257. The next prime is 61991323. The reversal of 61991273 is 37219916.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61905424 + 85849 = 7868^2 + 293^2 .

It is a cyclic number.

It is not a de Polignac number, because 61991273 - 2⁴ = 61991257 is a prime.

It is not a weakly prime, because it can be changed into another prime (61991173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30995636 + 30995637.

It is an arithmetic number, because the mean of its divisors is an integer number (30995637).

Almost surely, 2^61991273 is an apocalyptic number.

It is an amenable number.

61991273 is a deficient number, since it is larger than the sum of its proper divisors (1).

61991273 is an equidigital number, since it uses as much as digits as its factorization.

61991273 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20412, while the sum is 38.

The square root of 61991273 is about 7873.4536894555. The cubic root of 61991273 is about 395.7705899246.

The spelling of 61991273 in words is "sixty-one million, nine hundred ninety-one thousand, two hundred seventy-three".