20967491 has 4 divisors (see below), whose sum is σ = 20976912. Its totient is φ = 20958072.

The previous prime is 20967487. The next prime is 20967497. The reversal of 20967491 is 19476902.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 19476902 = 2 ⋅9738451.

It is a cyclic number.

It is not a de Polignac number, because 20967491 - 2² = 20967487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20967497) 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, 701 + ... + 6513.

It is an arithmetic number, because the mean of its divisors is an integer number (5244228).

Almost surely, 2^20967491 is an apocalyptic number.

20967491 is a deficient number, since it is larger than the sum of its proper divisors (9421).

20967491 is an equidigital number, since it uses as much as digits as its factorization.

20967491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9420.

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 20967491 is about 4579.0272984554. The cubic root of 20967491 is about 275.7499792456.

The spelling of 20967491 in words is "twenty million, nine hundred sixty-seven thousand, four hundred ninety-one".