20451678 has 32 divisors (see below), whose sum is σ = 44620800. Its totient is φ = 6211296.

The previous prime is 20451677. The next prime is 20451679. The reversal of 20451678 is 87615402.

It is an interprime number because it is at equal distance from previous prime (20451677) and next prime (20451679).

It is a super-2 number, since 2×20451678² = 836542266031368, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20451677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4503 + ... + 7821.

It is an arithmetic number, because the mean of its divisors is an integer number (1394400).

Almost surely, 2^20451678 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20451678, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22310400).

20451678 is an abundant number, since it is smaller than the sum of its proper divisors (24169122).

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

20451678 is a wasteful number, since it uses less digits than its factorization.

20451678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3416.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 20451678 is about 4522.3531485279. The cubic root of 20451678 is about 273.4699736540.

The spelling of 20451678 in words is "twenty million, four hundred fifty-one thousand, six hundred seventy-eight".