61717321 has 2 divisors, whose sum is σ = 61717322. Its totient is φ = 61717320.

The previous prime is 61717277. The next prime is 61717333. The reversal of 61717321 is 12371716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61011721 + 705600 = 7811^2 + 840^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61717321 is a prime.

It is a super-2 number, since 2×61717321² = 7618055422834082, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61717321.

It is not a weakly prime, because it can be changed into another prime (61717391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30858660 + 30858661.

It is an arithmetic number, because the mean of its divisors is an integer number (30858661).

Almost surely, 2^61717321 is an apocalyptic number.

It is an amenable number.

61717321 is a deficient number, since it is larger than the sum of its proper divisors (1).

61717321 is an equidigital number, since it uses as much as digits as its factorization.

61717321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1764, while the sum is 28.

The square root of 61717321 is about 7856.0372326002. The cubic root of 61717321 is about 395.1867321985.

The spelling of 61717321 in words is "sixty-one million, seven hundred seventeen thousand, three hundred twenty-one".