9690236721 has 81 divisors (see below), whose sum is σ = 16341586443. Its totient is φ = 5528334240.

The previous prime is 9690236719. The next prime is 9690236761. The reversal of 9690236721 is 1276320969.

It is a happy number.

The square root of 9690236721 is 98439.

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

It can be written as a sum of positive squares in only one way, i.e., 2840357025 + 6849879696 = 53295^2 + 82764^2 .

It is not a de Polignac number, because 9690236721 - 2¹ = 9690236719 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9690236761) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 61721175 + ... + 61721331.

Almost surely, 2^9690236721 is an apocalyptic number.

9690236721 is the 98439-th square number.

9690236721 is the 49220-th centered octagonal number.

It is an amenable number.

9690236721 is a deficient number, since it is larger than the sum of its proper divisors (6651349722).

9690236721 is a wasteful number, since it uses less digits than its factorization.

9690236721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 190 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The cubic root of 9690236721 is about 2131.9554673239.

The spelling of 9690236721 in words is "nine billion, six hundred ninety million, two hundred thirty-six thousand, seven hundred twenty-one".