21376416 has 48 divisors (see below), whose sum is σ = 57492288. Its totient is φ = 6950400.

The previous prime is 21376409. The next prime is 21376423. The reversal of 21376416 is 61467312.

It is an interprime number because it is at equal distance from previous prime (21376409) and next prime (21376423).

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-4 number, since 4×21376416⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

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, 1221 + ... + 6651.

It is an arithmetic number, because the mean of its divisors is an integer number (1197756).

Almost surely, 2^21376416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21376416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28746144).

21376416 is an abundant number, since it is smaller than the sum of its proper divisors (36115872).

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

21376416 is a wasteful number, since it uses less digits than its factorization.

21376416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5485 (or 5477 counting only the distinct ones).

The product of its digits is 6048, while the sum is 30.

The square root of 21376416 is about 4623.4636367122. The cubic root of 21376416 is about 277.5310832806.

The spelling of 21376416 in words is "twenty-one million, three hundred seventy-six thousand, four hundred sixteen".