21017401 has 4 divisors (see below), whose sum is σ = 22123600. Its totient is φ = 19911204.

The previous prime is 21017371. The next prime is 21017407. The reversal of 21017401 is 10471012.

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 21017401 - 2⁷ = 21017273 is a prime.

It is a super-2 number, since 2×21017401² = 883462289589602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21017407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553071 + ... + 553108.

It is an arithmetic number, because the mean of its divisors is an integer number (5530900).

Almost surely, 2^21017401 is an apocalyptic number.

It is an amenable number.

21017401 is a deficient number, since it is larger than the sum of its proper divisors (1106199).

21017401 is a wasteful number, since it uses less digits than its factorization.

21017401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106198.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21017401 is about 4584.4739065677. The cubic root of 21017401 is about 275.9685998374.

Adding to 21017401 its reverse (10471012), we get a palindrome (31488413).

The spelling of 21017401 in words is "twenty-one million, seventeen thousand, four hundred one".