61720942969 has 9 divisors (see below), whose sum is σ = 71799854661. Its totient is φ = 52902174780.

The previous prime is 61720942931. The next prime is 61720942993. The reversal of 61720942969 is 96924902716.

The square root of 61720942969 is 248437.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 61720942969 - 2⁹ = 61720942457 is a prime.

It is a super-2 number, since 2×61720942969² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61720942669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1721314 + ... + 1756804.

It is an arithmetic number, because the mean of its divisors is an integer number (7977761629).

Almost surely, 2^61720942969 is an apocalyptic number.

61720942969 is the 248437-th square number.

61720942969 is the 124219-th centered octagonal number.

It is an amenable number.

61720942969 is a deficient number, since it is larger than the sum of its proper divisors (10078911692).

61720942969 is an frugal number, since it uses more digits than its factorization.

61720942969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70996 (or 35498 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 55.

The spelling of 61720942969 in words is "sixty-one billion, seven hundred twenty million, nine hundred forty-two thousand, nine hundred sixty-nine".