13121657 has 2 divisors, whose sum is σ = 13121658. Its totient is φ = 13121656.

The previous prime is 13121639. The next prime is 13121683. The reversal of 13121657 is 75612131.

It is an a-pointer prime, because the next prime (13121683) can be obtained adding 13121657 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7284601 + 5837056 = 2699^2 + 2416^2 .

It is a cyclic number.

It is not a de Polignac number, because 13121657 - 2⁶ = 13121593 is a prime.

It is not a weakly prime, because it can be changed into another prime (13121257) 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, 6560828 + 6560829.

It is an arithmetic number, because the mean of its divisors is an integer number (6560829).

Almost surely, 2^13121657 is an apocalyptic number.

It is an amenable number.

13121657 is a deficient number, since it is larger than the sum of its proper divisors (1).

13121657 is an equidigital number, since it uses as much as digits as its factorization.

13121657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 26.

The square root of 13121657 is about 3622.3827793319. The cubic root of 13121657 is about 235.8646703299.

Adding to 13121657 its reverse (75612131), we get a palindrome (88733788).

The spelling of 13121657 in words is "thirteen million, one hundred twenty-one thousand, six hundred fifty-seven".