20280878 has 4 divisors (see below), whose sum is σ = 30421320. Its totient is φ = 10140438.

The previous prime is 20280877. The next prime is 20280893. The reversal of 20280878 is 87808202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87808202 = 2 ⋅43904101.

It is a super-2 number, since 2×20280878² = 822628024901768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20280877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5070218 + ... + 5070221.

It is an arithmetic number, because the mean of its divisors is an integer number (7605330).

Almost surely, 2^20280878 is an apocalyptic number.

20280878 is a deficient number, since it is larger than the sum of its proper divisors (10140442).

20280878 is a wasteful number, since it uses less digits than its factorization.

20280878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10140441.

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 20280878 is about 4503.4295819964. The cubic root of 20280878 is about 272.7065594303.

The spelling of 20280878 in words is "twenty million, two hundred eighty thousand, eight hundred seventy-eight".