20408986 has 8 divisors (see below), whose sum is σ = 32968404. Its totient is φ = 9419520.

The previous prime is 20408957. The next prime is 20408987. The reversal of 20408986 is 68980402.

It can be written as a sum of positive squares in 2 ways, for example, as 18361225 + 2047761 = 4285^2 + 1431^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20408987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 392455 + ... + 392506.

Almost surely, 2^20408986 is an apocalyptic number.

20408986 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20408986 is a deficient number, since it is larger than the sum of its proper divisors (12559418).

20408986 is a wasteful number, since it uses less digits than its factorization.

20408986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784976.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 20408986 is about 4517.6305736525. The cubic root of 20408986 is about 273.2795554852.

It can be divided in two parts, 2040 and 8986, that added together give a triangular number (11026 = T₁₄₈).

The spelling of 20408986 in words is "twenty million, four hundred eight thousand, nine hundred eighty-six".