20831078 has 4 divisors (see below), whose sum is σ = 31246620. Its totient is φ = 10415538.

The previous prime is 20831053. The next prime is 20831093. The reversal of 20831078 is 87013802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87013802 = 2 ⋅43506901.

It is a self number, because there is not a number n which added to its sum of digits gives 20831078.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5207768 + ... + 5207771.

It is an arithmetic number, because the mean of its divisors is an integer number (7811655).

Almost surely, 2^20831078 is an apocalyptic number.

20831078 is a deficient number, since it is larger than the sum of its proper divisors (10415542).

20831078 is a wasteful number, since it uses less digits than its factorization.

20831078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10415541.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 20831078 is about 4564.1075798013. The cubic root of 20831078 is about 275.1506744541.

The spelling of 20831078 in words is "twenty million, eight hundred thirty-one thousand, seventy-eight".