20451330 has 48 divisors (see below), whose sum is σ = 53464320. Its totient is φ = 5423904.

The previous prime is 20451329. The next prime is 20451373. The reversal of 20451330 is 3315402.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19561 + ... + 20579.

It is an arithmetic number, because the mean of its divisors is an integer number (1113840).

Almost surely, 2^20451330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20451330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26732160).

20451330 is an abundant number, since it is smaller than the sum of its proper divisors (33012990).

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

20451330 is a wasteful number, since it uses less digits than its factorization.

20451330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255 (or 1252 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 20451330 is about 4522.3146728197. The cubic root of 20451330 is about 273.4684225492.

Adding to 20451330 its reverse (3315402), we get a palindrome (23766732).

It can be divided in two parts, 2045 and 1330, that added together give a cube (3375 = 15³).

The spelling of 20451330 in words is "twenty million, four hundred fifty-one thousand, three hundred thirty".