61729321 has 2 divisors, whose sum is σ = 61729322. Its totient is φ = 61729320.

The previous prime is 61729307. The next prime is 61729331. The reversal of 61729321 is 12392716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38303721 + 23425600 = 6189^2 + 4840^2 .

It is a cyclic number.

It is not a de Polignac number, because 61729321 - 2⁵ = 61729289 is a prime.

It is a super-2 number, since 2×61729321² = 7621018142242082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61729331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30864660 + 30864661.

It is an arithmetic number, because the mean of its divisors is an integer number (30864661).

Almost surely, 2^61729321 is an apocalyptic number.

It is an amenable number.

61729321 is a deficient number, since it is larger than the sum of its proper divisors (1).

61729321 is an equidigital number, since it uses as much as digits as its factorization.

61729321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 31.

The square root of 61729321 is about 7856.8009393137. The cubic root of 61729321 is about 395.2123432339.

The spelling of 61729321 in words is "sixty-one million, seven hundred twenty-nine thousand, three hundred twenty-one".