20546991 has 12 divisors (see below), whose sum is σ = 30369768. Its totient is φ = 13379184.

The previous prime is 20546983. The next prime is 20547013. The reversal of 20546991 is 19964502.

20546991 is a `hidden beast` number, since 20 + 546 + 9 + 91 = 666.

It is not a de Polignac number, because 20546991 - 2³ = 20546983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20546921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26160 + ... + 26933.

It is an arithmetic number, because the mean of its divisors is an integer number (2530814).

Almost surely, 2^20546991 is an apocalyptic number.

20546991 is a deficient number, since it is larger than the sum of its proper divisors (9822777).

20546991 is a wasteful number, since it uses less digits than its factorization.

20546991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53142 (or 53139 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 20546991 is about 4532.8788865356. The cubic root of 20546991 is about 273.8941418913.

It can be divided in two parts, 2054 and 6991, that added together give a triangular number (9045 = T₁₃₄).

The spelling of 20546991 in words is "twenty million, five hundred forty-six thousand, nine hundred ninety-one".