9721009551 has 32 divisors (see below), whose sum is σ = 14360032512. Its totient is φ = 5800194560.

The previous prime is 9721009541. The next prime is 9721009559. The reversal of 9721009551 is 1559001279.

It is a cyclic number.

It is not a de Polignac number, because 9721009551 - 2⁷ = 9721009423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9721009559) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 796471 + ... + 808583.

It is an arithmetic number, because the mean of its divisors is an integer number (448751016).

Almost surely, 2^9721009551 is an apocalyptic number.

9721009551 is a deficient number, since it is larger than the sum of its proper divisors (4639022961).

9721009551 is a wasteful number, since it uses less digits than its factorization.

9721009551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12503.

The product of its (nonzero) digits is 28350, while the sum is 39.

The square root of 9721009551 is about 98595.1801611012. The cubic root of 9721009551 is about 2134.2098662512.

The spelling of 9721009551 in words is "nine billion, seven hundred twenty-one million, nine thousand, five hundred fifty-one".