20781494 has 16 divisors (see below), whose sum is σ = 32461728. Its totient is φ = 9968832.

The previous prime is 20781493. The next prime is 20781517. The reversal of 20781494 is 49418702.

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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3479 + ... + 7325.

It is an arithmetic number, because the mean of its divisors is an integer number (2028858).

Almost surely, 2^20781494 is an apocalyptic number.

20781494 is a deficient number, since it is larger than the sum of its proper divisors (11680234).

20781494 is a wasteful number, since it uses less digits than its factorization.

20781494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3959.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20781494 is about 4558.6723944587. The cubic root of 20781494 is about 274.9321882385.

The spelling of 20781494 in words is "twenty million, seven hundred eighty-one thousand, four hundred ninety-four".