9702720861 has 16 divisors (see below), whose sum is σ = 13620003840. Its totient is φ = 6127066800.

The previous prime is 9702720827. The next prime is 9702720871. The reversal of 9702720861 is 1680272079.

9702720861 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-9702720861 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9702720871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 574386 + ... + 591036.

It is an arithmetic number, because the mean of its divisors is an integer number (851250240).

Almost surely, 2^9702720861 is an apocalyptic number.

It is an amenable number.

9702720861 is a deficient number, since it is larger than the sum of its proper divisors (3917282979).

9702720861 is a wasteful number, since it uses less digits than its factorization.

9702720861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26896.

The product of its (nonzero) digits is 84672, while the sum is 42.

The square root of 9702720861 is about 98502.3901283619. The cubic root of 9702720861 is about 2132.8706224310.

The spelling of 9702720861 in words is "nine billion, seven hundred two million, seven hundred twenty thousand, eight hundred sixty-one".