13650821 has 4 divisors (see below), whose sum is σ = 13941312. Its totient is φ = 13360332.

The previous prime is 13650811. The next prime is 13650829. The reversal of 13650821 is 12805631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12805631 = 71 ⋅180361.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13650821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13650829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145175 + ... + 145268.

It is an arithmetic number, because the mean of its divisors is an integer number (3485328).

Almost surely, 2^13650821 is an apocalyptic number.

It is an amenable number.

13650821 is a deficient number, since it is larger than the sum of its proper divisors (290491).

13650821 is an equidigital number, since it uses as much as digits as its factorization.

13650821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290490.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 13650821 is about 3694.7017470968. The cubic root of 13650821 is about 238.9935923774.

The spelling of 13650821 in words is "thirteen million, six hundred fifty thousand, eight hundred twenty-one".