21370671 has 24 divisors (see below), whose sum is σ = 35569664. Its totient is φ = 12111120.

The previous prime is 21370667. The next prime is 21370681. The reversal of 21370671 is 17607312.

21370671 = 1229² + 1230² + ... + 1242².

It is not a de Polignac number, because 21370671 - 2² = 21370667 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21370621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6666 + ... + 9336.

Almost surely, 2^21370671 is an apocalyptic number.

21370671 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21370671 is a deficient number, since it is larger than the sum of its proper divisors (14198993).

21370671 is a wasteful number, since it uses less digits than its factorization.

21370671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2811 (or 2808 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 21370671 is about 4622.8423074987. The cubic root of 21370671 is about 277.5062185117.

Adding to 21370671 its reverse (17607312), we get a palindrome (38977983).

The spelling of 21370671 in words is "twenty-one million, three hundred seventy thousand, six hundred seventy-one".