21853480 has 32 divisors (see below), whose sum is σ = 53641440. Its totient is φ = 7946560.

The previous prime is 21853399. The next prime is 21853487. The reversal of 21853480 is 8435812.

It is a super-2 number, since 2×21853480² = 955149176220800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21853487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24394 + ... + 25273.

It is an arithmetic number, because the mean of its divisors is an integer number (1676295).

Almost surely, 2^21853480 is an apocalyptic number.

21853480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21853480 is an abundant number, since it is smaller than the sum of its proper divisors (31787960).

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

21853480 is a wasteful number, since it uses less digits than its factorization.

21853480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49689 (or 49685 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 21853480 is about 4674.7705826062. The cubic root of 21853480 is about 279.5804942447.

It can be divided in two parts, 2185 and 3480, that added together give a palindrome (5665).

The spelling of 21853480 in words is "twenty-one million, eight hundred fifty-three thousand, four hundred eighty".