21494730 has 16 divisors (see below), whose sum is σ = 51587424. Its totient is φ = 5731920.

The previous prime is 21494729. The next prime is 21494779. The reversal of 21494730 is 3749412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 716491 = 21494730 / (2 + 1 + 4 + 9 + 4 + 7 + 3 + 0).

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, 358216 + ... + 358275.

It is an arithmetic number, because the mean of its divisors is an integer number (3224214).

Almost surely, 2^21494730 is an apocalyptic number.

21494730 is an abundant number, since it is smaller than the sum of its proper divisors (30092694).

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

21494730 is a wasteful number, since it uses less digits than its factorization.

21494730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716501.

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

The square root of 21494730 is about 4636.2409342052. The cubic root of 21494730 is about 278.0421670593.

The spelling of 21494730 in words is "twenty-one million, four hundred ninety-four thousand, seven hundred thirty".