13787021 has 2 divisors, whose sum is σ = 13787022. Its totient is φ = 13787020.

The previous prime is 13787003. The next prime is 13787023. The reversal of 13787021 is 12078731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8094025 + 5692996 = 2845^2 + 2386^2 .

It is a cyclic number.

It is not a de Polignac number, because 13787021 - 2⁶ = 13786957 is a prime.

Together with 13787023, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₈₉₇₁₄₀ and since 13787021 and 897140 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13787023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6893510 + 6893511.

It is an arithmetic number, because the mean of its divisors is an integer number (6893511).

Almost surely, 2^13787021 is an apocalyptic number.

It is an amenable number.

13787021 is a deficient number, since it is larger than the sum of its proper divisors (1).

13787021 is an equidigital number, since it uses as much as digits as its factorization.

13787021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 13787021 is about 3713.0877985849. The cubic root of 13787021 is about 239.7858100587.

The spelling of 13787021 in words is "thirteen million, seven hundred eighty-seven thousand, twenty-one".