20787874 has 4 divisors (see below), whose sum is σ = 31181814. Its totient is φ = 10393936.

The previous prime is 20787869. The next prime is 20787901. The reversal of 20787874 is 47878702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47878702 = 2 ⋅23939351.

It can be written as a sum of positive squares in only one way, i.e., 18705625 + 2082249 = 4325^2 + 1443^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20787874.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5196967 + ... + 5196970.

Almost surely, 2^20787874 is an apocalyptic number.

20787874 is a deficient number, since it is larger than the sum of its proper divisors (10393940).

20787874 is a wasteful number, since it uses less digits than its factorization.

20787874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10393939.

The product of its (nonzero) digits is 175616, while the sum is 43.

The square root of 20787874 is about 4559.3721058935. The cubic root of 20787874 is about 274.9603204457.

The spelling of 20787874 in words is "twenty million, seven hundred eighty-seven thousand, eight hundred seventy-four".