13507721 has 2 divisors, whose sum is σ = 13507722. Its totient is φ = 13507720.

The previous prime is 13507717. The next prime is 13507751. The reversal of 13507721 is 12770531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12924025 + 583696 = 3595^2 + 764^2 .

It is a cyclic number.

It is not a de Polignac number, because 13507721 - 2² = 13507717 is a prime.

It is a super-2 number, since 2×13507721² = 364917053227682, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13507751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6753860 + 6753861.

It is an arithmetic number, because the mean of its divisors is an integer number (6753861).

Almost surely, 2^13507721 is an apocalyptic number.

It is an amenable number.

13507721 is a deficient number, since it is larger than the sum of its proper divisors (1).

13507721 is an equidigital number, since it uses as much as digits as its factorization.

13507721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1470, while the sum is 26.

The square root of 13507721 is about 3675.2851590047. The cubic root of 13507721 is about 238.1555429348.

The spelling of 13507721 in words is "thirteen million, five hundred seven thousand, seven hundred twenty-one".