20491396 has 6 divisors (see below), whose sum is σ = 35859950. Its totient is φ = 10245696.

The previous prime is 20491379. The next prime is 20491399. The reversal of 20491396 is 69319402.

It can be written as a sum of positive squares in only one way, i.e., 19236996 + 1254400 = 4386^2 + 1120^2 .

It is not an unprimeable number, because it can be changed into a prime (20491399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2561421 + ... + 2561428.

Almost surely, 2^20491396 is an apocalyptic number.

It is an amenable number.

20491396 is a deficient number, since it is larger than the sum of its proper divisors (15368554).

20491396 is a wasteful number, since it uses less digits than its factorization.

20491396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5122853 (or 5122851 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 20491396 is about 4526.7423165009. The cubic root of 20491396 is about 273.6468891572.

The spelling of 20491396 in words is "twenty million, four hundred ninety-one thousand, three hundred ninety-six".