20408451 has 24 divisors (see below), whose sum is σ = 33324480. Its totient is φ = 11046672.

The previous prime is 20408419. The next prime is 20408459. The reversal of 20408451 is 15480402.

It is not a de Polignac number, because 20408451 - 2⁵ = 20408419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20408459) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 861 + ... + 6446.

It is an arithmetic number, because the mean of its divisors is an integer number (1388520).

Almost surely, 2^20408451 is an apocalyptic number.

20408451 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20408451 is a deficient number, since it is larger than the sum of its proper divisors (12916029).

20408451 is a wasteful number, since it uses less digits than its factorization.

20408451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7343 (or 7336 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 20408451 is about 4517.5713608088. The cubic root of 20408451 is about 273.2771675527.

Adding to 20408451 its reverse (15480402), we get a palindrome (35888853).

The spelling of 20408451 in words is "twenty million, four hundred eight thousand, four hundred fifty-one".