21371530 has 8 divisors (see below), whose sum is σ = 38468772. Its totient is φ = 8548608.

The previous prime is 21371509. The next prime is 21371551. The reversal of 21371530 is 3517312.

It is an interprime number because it is at equal distance from previous prime (21371509) and next prime (21371551).

It can be written as a sum of positive squares in 2 ways, for example, as 21132409 + 239121 = 4597^2 + 489^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1068567 + ... + 1068586.

Almost surely, 2^21371530 is an apocalyptic number.

21371530 is a deficient number, since it is larger than the sum of its proper divisors (17097242).

21371530 is a wasteful number, since it uses less digits than its factorization.

21371530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2137160.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 21371530 is about 4622.9352147743. The cubic root of 21371530 is about 277.5099366082.

Adding to 21371530 its reverse (3517312), we get a palindrome (24888842).

The spelling of 21371530 in words is "twenty-one million, three hundred seventy-one thousand, five hundred thirty".