21449280 has 56 divisors (see below), whose sum is σ = 68104512. Its totient is φ = 5719552.

The previous prime is 21449279. The next prime is 21449293. The reversal of 21449280 is 8294412.

It is a super-2 number, since 2×21449280² = 920143225036800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10212 + ... + 12131.

It is an arithmetic number, because the mean of its divisors is an integer number (1216152).

Almost surely, 2^21449280 is an apocalyptic number.

21449280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21449280 is an abundant number, since it is smaller than the sum of its proper divisors (46655232).

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

21449280 is a wasteful number, since it uses less digits than its factorization.

21449280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22363 (or 22353 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 21449280 is about 4631.3367400784. The cubic root of 21449280 is about 277.8460579999.

It can be divided in two parts, 214 and 49280, that added together give a palindrome (49494).

The spelling of 21449280 in words is "twenty-one million, four hundred forty-nine thousand, two hundred eighty".