61721019 has 12 divisors (see below), whose sum is σ = 92227200. Its totient is φ = 39728304.

The previous prime is 61721017. The next prime is 61721027. The reversal of 61721019 is 91012716.

It is not a de Polignac number, because 61721019 - 2¹ = 61721017 is a prime.

It is a super-2 number, since 2×61721019² = 7618968372796722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61720983 and 61721001.

It is not an unprimeable number, because it can be changed into a prime (61721017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117979 + ... + 118500.

It is an arithmetic number, because the mean of its divisors is an integer number (7685600).

Almost surely, 2^61721019 is an apocalyptic number.

61721019 is a deficient number, since it is larger than the sum of its proper divisors (30506181).

61721019 is a wasteful number, since it uses less digits than its factorization.

61721019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236514 (or 236511 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The square root of 61721019 is about 7856.2725894663. The cubic root of 61721019 is about 395.1946250198.

The spelling of 61721019 in words is "sixty-one million, seven hundred twenty-one thousand, nineteen".