13121971 has 2 divisors, whose sum is σ = 13121972. Its totient is φ = 13121970.

The previous prime is 13121921. The next prime is 13121987. The reversal of 13121971 is 17912131.

13121971 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 13121971 - 2¹⁷ = 12990899 is a prime.

It is a super-2 number, since 2×13121971² = 344372245849682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13121921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6560985 + 6560986.

It is an arithmetic number, because the mean of its divisors is an integer number (6560986).

Almost surely, 2^13121971 is an apocalyptic number.

13121971 is a deficient number, since it is larger than the sum of its proper divisors (1).

13121971 is an equidigital number, since it uses as much as digits as its factorization.

13121971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 378, while the sum is 25.

The square root of 13121971 is about 3622.4261207097. The cubic root of 13121971 is about 235.8665517212.

The spelling of 13121971 in words is "thirteen million, one hundred twenty-one thousand, nine hundred seventy-one".