61381997 has 2 divisors, whose sum is σ = 61381998. Its totient is φ = 61381996.

The previous prime is 61381993. The next prime is 61382011. The reversal of 61381997 is 79918316.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58461316 + 2920681 = 7646^2 + 1709^2 .

It is a cyclic number.

It is not a de Polignac number, because 61381997 - 2² = 61381993 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61381993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30690998 + 30690999.

It is an arithmetic number, because the mean of its divisors is an integer number (30690999).

Almost surely, 2^61381997 is an apocalyptic number.

It is an amenable number.

61381997 is a deficient number, since it is larger than the sum of its proper divisors (1).

61381997 is an equidigital number, since it uses as much as digits as its factorization.

61381997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 44.

The square root of 61381997 is about 7834.6663617540. Note that the first 3 decimals coincide. The cubic root of 61381997 is about 394.4697194469.

The spelling of 61381997 in words is "sixty-one million, three hundred eighty-one thousand, nine hundred ninety-seven".