21620376 has 48 divisors (see below), whose sum is σ = 59810400. Its totient is φ = 7052352.

The previous prime is 21620369. The next prime is 21620383. The reversal of 21620376 is 67302612.

It is a happy number.

21620376 is a `hidden beast` number, since 2 + 1 + 620 + 37 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (21620369) and next prime (21620383).

It is a plaindrome in base 11.

It is a zygodrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190 + ... + 6578.

It is an arithmetic number, because the mean of its divisors is an integer number (1246050).

Almost surely, 2^21620376 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 21620376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29905200).

21620376 is an abundant number, since it is smaller than the sum of its proper divisors (38190024).

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

21620376 is a wasteful number, since it uses less digits than its factorization.

21620376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6448 (or 6441 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 21620376 is about 4649.7716072943. The cubic root of 21620376 is about 278.5828738042.

Adding to 21620376 its reverse (67302612), we get a palindrome (88922988).

The spelling of 21620376 in words is "twenty-one million, six hundred twenty thousand, three hundred seventy-six".