20249647 has 4 divisors (see below), whose sum is σ = 22090536. Its totient is φ = 18408760.

The previous prime is 20249641. The next prime is 20249651. The reversal of 20249647 is 74694202.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20249647 - 2⁷ = 20249519 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 (20249641) 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, 920428 + ... + 920449.

It is an arithmetic number, because the mean of its divisors is an integer number (5522634).

Almost surely, 2^20249647 is an apocalyptic number.

20249647 is a deficient number, since it is larger than the sum of its proper divisors (1840889).

20249647 is a wasteful number, since it uses less digits than its factorization.

20249647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1840888.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 20249647 is about 4499.9607776068. The cubic root of 20249647 is about 272.5665051043.

The spelling of 20249647 in words is "twenty million, two hundred forty-nine thousand, six hundred forty-seven".