20987394 has 8 divisors (see below), whose sum is σ = 41974800. Its totient is φ = 6995796.

The previous prime is 20987389. The next prime is 20987413. The reversal of 20987394 is 49378902.

It is a sphenic number, since it is the product of 3 distinct primes.

20987394 is an admirable number.

It is a super-2 number, since 2×20987394² = 880941413822472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1748944 + ... + 1748955.

It is an arithmetic number, because the mean of its divisors is an integer number (5246850).

Almost surely, 2^20987394 is an apocalyptic number.

20987394 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20987394 is a wasteful number, since it uses less digits than its factorization.

20987394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3497904.

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 20987394 is about 4581.2000611194. The cubic root of 20987394 is about 275.8372018292.

The spelling of 20987394 in words is "twenty million, nine hundred eighty-seven thousand, three hundred ninety-four".