20013949 has 4 divisors (see below), whose sum is σ = 20043936. Its totient is φ = 19983964.

The previous prime is 20013937. The next prime is 20013971. The reversal of 20013949 is 94931002.

It is a happy number.

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: 94931002 = 2 ⋅47465501.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20013949 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 (20013349) 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, 13969 + ... + 15334.

It is an arithmetic number, because the mean of its divisors is an integer number (5010984).

Almost surely, 2^20013949 is an apocalyptic number.

It is an amenable number.

20013949 is a deficient number, since it is larger than the sum of its proper divisors (29987).

20013949 is an equidigital number, since it uses as much as digits as its factorization.

20013949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29986.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20013949 is about 4473.6952287790. The cubic root of 20013949 is about 271.5048526797.

The spelling of 20013949 in words is "twenty million, thirteen thousand, nine hundred forty-nine".