20686390 has 8 divisors (see below), whose sum is σ = 37235520. Its totient is φ = 8274552.

The previous prime is 20686373. The next prime is 20686409. The reversal of 20686390 is 9368602.

It is a happy number.

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

It is a congruent number.

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, 1034310 + ... + 1034329.

It is an arithmetic number, because the mean of its divisors is an integer number (4654440).

Almost surely, 2^20686390 is an apocalyptic number.

20686390 is a deficient number, since it is larger than the sum of its proper divisors (16549130).

20686390 is a wasteful number, since it uses less digits than its factorization.

20686390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2068646.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 20686390 is about 4548.2293257926. The cubic root of 20686390 is about 274.5121488358.

The spelling of 20686390 in words is "twenty million, six hundred eighty-six thousand, three hundred ninety".