21627738 has 48 divisors (see below), whose sum is σ = 53820000. Its totient is φ = 6207840.

The previous prime is 21627737. The next prime is 21627743. The reversal of 21627738 is 83772612.

21627738 is a `hidden beast` number, since 21 + 627 + 7 + 3 + 8 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21627731) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 888 + ... + 6636.

It is an arithmetic number, because the mean of its divisors is an integer number (1121250).

Almost surely, 2^21627738 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21627738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26910000).

21627738 is an abundant number, since it is smaller than the sum of its proper divisors (32192262).

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

21627738 is a wasteful number, since it uses less digits than its factorization.

21627738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5787 (or 5784 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 21627738 is about 4650.5631917005. The cubic root of 21627738 is about 278.6144904972.

The spelling of 21627738 in words is "twenty-one million, six hundred twenty-seven thousand, seven hundred thirty-eight".