20781496 has 8 divisors (see below), whose sum is σ = 38965320. Its totient is φ = 10390744.

The previous prime is 20781493. The next prime is 20781517. The reversal of 20781496 is 69418702.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20781493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1298836 + ... + 1298851.

It is an arithmetic number, because the mean of its divisors is an integer number (4870665).

Almost surely, 2^20781496 is an apocalyptic number.

It is an amenable number.

20781496 is a deficient number, since it is larger than the sum of its proper divisors (18183824).

20781496 is a wasteful number, since it uses less digits than its factorization.

20781496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2597693 (or 2597689 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 20781496 is about 4558.6726138208. The cubic root of 20781496 is about 274.9321970582.

The spelling of 20781496 in words is "twenty million, seven hundred eighty-one thousand, four hundred ninety-six".