20451040 has 24 divisors (see below), whose sum is σ = 48315960. Its totient is φ = 8180352.

The previous prime is 20451037. The next prime is 20451059. The reversal of 20451040 is 4015402.

It is a Harshad number since it is a multiple of its sum of digits (16).

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, 63750 + ... + 64069.

It is an arithmetic number, because the mean of its divisors is an integer number (2013165).

Almost surely, 2^20451040 is an apocalyptic number.

20451040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20451040 is an abundant number, since it is smaller than the sum of its proper divisors (27864920).

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

20451040 is a wasteful number, since it uses less digits than its factorization.

20451040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127834 (or 127826 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 20451040 is about 4522.2826094794. The cubic root of 20451040 is about 273.4671299483.

Adding to 20451040 its reverse (4015402), we get a palindrome (24466442).

The spelling of 20451040 in words is "twenty million, four hundred fifty-one thousand, forty".