13700021 has 2 divisors, whose sum is σ = 13700022. Its totient is φ = 13700020.

The previous prime is 13700017. The next prime is 13700039. The reversal of 13700021 is 12000731.

13700021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11464996 + 2235025 = 3386^2 + 1495^2 .

It is an emirp because it is prime and its reverse (12000731) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13700021 - 2² = 13700017 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 13699969 and 13700005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13700081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6850010 + 6850011.

It is an arithmetic number, because the mean of its divisors is an integer number (6850011).

Almost surely, 2^13700021 is an apocalyptic number.

It is an amenable number.

13700021 is a deficient number, since it is larger than the sum of its proper divisors (1).

13700021 is an equidigital number, since it uses as much as digits as its factorization.

13700021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42, while the sum is 14.

The square root of 13700021 is about 3701.3539414652. The cubic root of 13700021 is about 239.2803733312.

Adding to 13700021 its reverse (12000731), we get a palindrome (25700752).

The spelling of 13700021 in words is "thirteen million, seven hundred thousand, twenty-one".