20491394 has 32 divisors (see below), whose sum is σ = 38541312. Its totient is φ = 7938000.

The previous prime is 20491379. The next prime is 20491399. The reversal of 20491394 is 49319402.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20491394.

It is not an unprimeable number, because it can be changed into a prime (20491399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41489 + ... + 41979.

It is an arithmetic number, because the mean of its divisors is an integer number (1204416).

Almost surely, 2^20491394 is an apocalyptic number.

20491394 is a deficient number, since it is larger than the sum of its proper divisors (18049918).

20491394 is a wasteful number, since it uses less digits than its factorization.

20491394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 20491394 is about 4526.7420955915. The cubic root of 20491394 is about 273.6468802544.

It can be divided in two parts, 2049 and 1394, that added together give a palindrome (3443).

The spelling of 20491394 in words is "twenty million, four hundred ninety-one thousand, three hundred ninety-four".