20494751 has 4 divisors (see below), whose sum is σ = 21155904. Its totient is φ = 19833600.

The previous prime is 20494739. The next prime is 20494753. The reversal of 20494751 is 15749402.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20494751 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 (20494753) 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, 330530 + ... + 330591.

It is an arithmetic number, because the mean of its divisors is an integer number (5288976).

Almost surely, 2^20494751 is an apocalyptic number.

20494751 is a deficient number, since it is larger than the sum of its proper divisors (661153).

20494751 is an equidigital number, since it uses as much as digits as its factorization.

20494751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661152.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 20494751 is about 4527.1128768786. The cubic root of 20494751 is about 273.6618228268.

The spelling of 20494751 in words is "twenty million, four hundred ninety-four thousand, seven hundred fifty-one".