21041651 has 8 divisors (see below), whose sum is σ = 21621264. Its totient is φ = 20465280.

The previous prime is 21041639. The next prime is 21041659. The reversal of 21041651 is 15614012.

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

It is a cyclic number.

It is not a de Polignac number, because 21041651 - 2¹⁰ = 21040627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21041659) 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 7 ways as a sum of consecutive naturals, for example, 18176 + ... + 19298.

It is an arithmetic number, because the mean of its divisors is an integer number (2702658).

Almost surely, 2^21041651 is an apocalyptic number.

21041651 is a deficient number, since it is larger than the sum of its proper divisors (579613).

21041651 is a wasteful number, since it uses less digits than its factorization.

21041651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1621.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 21041651 is about 4587.1179404938. The cubic root of 21041651 is about 276.0746971033.

Adding to 21041651 its reverse (15614012), we get a palindrome (36655663).

The spelling of 21041651 in words is "twenty-one million, forty-one thousand, six hundred fifty-one".