10615721 has 2 divisors, whose sum is σ = 10615722. Its totient is φ = 10615720.

The previous prime is 10615697. The next prime is 10615723. The reversal of 10615721 is 12751601.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6948496 + 3667225 = 2636^2 + 1915^2 .

It is an emirp because it is prime and its reverse (12751601) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10615721 - 2²² = 6421417 is a prime.

It is a super-2 number, since 2×10615721² = 225387064699682, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 10615723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 13.

It is not a weakly prime, because it can be changed into another prime (10615723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5307860 + 5307861.

It is an arithmetic number, because the mean of its divisors is an integer number (5307861).

Almost surely, 2^10615721 is an apocalyptic number.

It is an amenable number.

10615721 is a deficient number, since it is larger than the sum of its proper divisors (1).

10615721 is an equidigital number, since it uses as much as digits as its factorization.

10615721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 10615721 is about 3258.1775580837. The cubic root of 10615721 is about 219.7774678199. Note that the first 3 decimals are identical.

The spelling of 10615721 in words is "ten million, six hundred fifteen thousand, seven hundred twenty-one".