21374370 has 48 divisors (see below), whose sum is σ = 56634552. Its totient is φ = 5591040.

The previous prime is 21374357. The next prime is 21374377. The reversal of 21374370 is 7347312.

It can be written as a sum of positive squares in 4 ways, for example, as 20548089 + 826281 = 4533^2 + 909^2 .

It is not an unprimeable number, because it can be changed into a prime (21374377) 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, 2530 + ... + 7010.

Almost surely, 2^21374370 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21374370, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28317276).

21374370 is an abundant number, since it is smaller than the sum of its proper divisors (35260182).

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

21374370 is a wasteful number, since it uses less digits than its factorization.

21374370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4547 (or 4544 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 27.

The square root of 21374370 is about 4623.2423687278. The cubic root of 21374370 is about 277.5222285578.

The spelling of 21374370 in words is "twenty-one million, three hundred seventy-four thousand, three hundred seventy".