20689278 has 16 divisors (see below), whose sum is σ = 42341376. Its totient is φ = 6735960.

The previous prime is 20689247. The next prime is 20689313. The reversal of 20689278 is 87298602.

It is a happy number.

It is a super-2 number, since 2×20689278² = 856092448322568, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39838 + ... + 40353.

It is an arithmetic number, because the mean of its divisors is an integer number (2646336).

Almost surely, 2^20689278 is an apocalyptic number.

20689278 is an abundant number, since it is smaller than the sum of its proper divisors (21652098).

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

20689278 is a wasteful number, since it uses less digits than its factorization.

20689278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80239.

The product of its (nonzero) digits is 96768, while the sum is 42.

The square root of 20689278 is about 4548.5468009025. The cubic root of 20689278 is about 274.5249230027.

The spelling of 20689278 in words is "twenty million, six hundred eighty-nine thousand, two hundred seventy-eight".