9721951 has 2 divisors, whose sum is σ = 9721952. Its totient is φ = 9721950.

The previous prime is 9721937. The next prime is 9721969. The reversal of 9721951 is 1591279.

9721951 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9721951 - 2⁵ = 9721919 is a prime.

9721951 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9721991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4860975 + 4860976.

It is an arithmetic number, because the mean of its divisors is an integer number (4860976).

Almost surely, 2^9721951 is an apocalyptic number.

9721951 is a deficient number, since it is larger than the sum of its proper divisors (1).

9721951 is an equidigital number, since it uses as much as digits as its factorization.

9721951 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5670, while the sum is 34.

The square root of 9721951 is about 3118.0043296955. The cubic root of 9721951 is about 213.4278761184.

It can be divided in two parts, 972195 and 1, that added together give a square (972196 = 986²).

The spelling of 9721951 in words is "nine million, seven hundred twenty-one thousand, nine hundred fifty-one".