21487370 has 8 divisors (see below), whose sum is σ = 38677284. Its totient is φ = 8594944.

The previous prime is 21487351. The next prime is 21487373. The reversal of 21487370 is 7378412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21446161 + 41209 = 4631^2 + 203^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21487373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1074359 + ... + 1074378.

Almost surely, 2^21487370 is an apocalyptic number.

21487370 is a deficient number, since it is larger than the sum of its proper divisors (17189914).

21487370 is a wasteful number, since it uses less digits than its factorization.

21487370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2148744.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 21487370 is about 4635.4471197502. The cubic root of 21487370 is about 278.0104286756.

The spelling of 21487370 in words is "twenty-one million, four hundred eighty-seven thousand, three hundred seventy".