21017377 has 4 divisors (see below), whose sum is σ = 21931200. Its totient is φ = 20103556.

The previous prime is 21017371. The next prime is 21017407. The reversal of 21017377 is 77371012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21017377 - 2¹⁵ = 20984609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21017371) 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, 456877 + ... + 456922.

It is an arithmetic number, because the mean of its divisors is an integer number (5482800).

Almost surely, 2^21017377 is an apocalyptic number.

It is an amenable number.

21017377 is a deficient number, since it is larger than the sum of its proper divisors (913823).

21017377 is an equidigital number, since it uses as much as digits as its factorization.

21017377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913822.

The product of its (nonzero) digits is 2058, while the sum is 28.

The square root of 21017377 is about 4584.4712890365. The cubic root of 21017377 is about 275.9684947935.

Adding to 21017377 its reverse (77371012), we get a palindrome (98388389).

The spelling of 21017377 in words is "twenty-one million, seventeen thousand, three hundred seventy-seven".