21449376 has 144 divisors (see below), whose sum is σ = 69759144. Its totient is φ = 6193152.

The previous prime is 21449353. The next prime is 21449387. The reversal of 21449376 is 67394412.

It can be written as a sum of positive squares in 4 ways, for example, as 15397776 + 6051600 = 3924^2 + 2460^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21449376.

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, 63480 + ... + 63816.

Almost surely, 2^21449376 is an apocalyptic number.

21449376 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21449376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34879572).

21449376 is an abundant number, since it is smaller than the sum of its proper divisors (48309768).

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

21449376 is a wasteful number, since it uses less digits than its factorization.

21449376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383 (or 372 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21449376 is about 4631.3471042452. The cubic root of 21449376 is about 277.8464725155.

The spelling of 21449376 in words is "twenty-one million, four hundred forty-nine thousand, three hundred seventy-six".