20981994 has 32 divisors (see below), whose sum is σ = 45994176. Its totient is φ = 6328320.

The previous prime is 20981971. The next prime is 20981999. The reversal of 20981994 is 49918902.

It is not an unprimeable number, because it can be changed into a prime (20981999) 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, 16344 + ... + 17580.

It is an arithmetic number, because the mean of its divisors is an integer number (1437318).

Almost surely, 2^20981994 is an apocalyptic number.

20981994 is an abundant number, since it is smaller than the sum of its proper divisors (25012182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20981994 is a wasteful number, since it uses less digits than its factorization.

20981994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1510.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 20981994 is about 4580.6106579800. The cubic root of 20981994 is about 275.8135424100.

The spelling of 20981994 in words is "twenty million, nine hundred eighty-one thousand, nine hundred ninety-four".