21556041 has 16 divisors (see below), whose sum is σ = 31046400. Its totient is φ = 13224960.

The previous prime is 21556027. The next prime is 21556057. The reversal of 21556041 is 14065512.

It is not a de Polignac number, because 21556041 - 2⁵ = 21556009 is a prime.

It is a super-3 number, since 3×21556041³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21556021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16896 + ... + 18126.

It is an arithmetic number, because the mean of its divisors is an integer number (1940400).

Almost surely, 2^21556041 is an apocalyptic number.

It is an amenable number.

21556041 is a deficient number, since it is larger than the sum of its proper divisors (9490359).

21556041 is a wasteful number, since it uses less digits than its factorization.

21556041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1696.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21556041 is about 4642.8483714203. The cubic root of 21556041 is about 278.3062761496.

The spelling of 21556041 in words is "twenty-one million, five hundred fifty-six thousand, forty-one".