21997041 has 16 divisors (see below), whose sum is σ = 33680640. Its totient is φ = 12629520.

The previous prime is 21997021. The next prime is 21997043. The reversal of 21997041 is 14079912.

It is not a de Polignac number, because 21997041 - 2⁵ = 21997009 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 21996993 and 21997011.

It is not an unprimeable number, because it can be changed into a prime (21997043) 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, 16915 + ... + 18168.

It is an arithmetic number, because the mean of its divisors is an integer number (2105040).

Almost surely, 2^21997041 is an apocalyptic number.

It is an amenable number.

21997041 is a deficient number, since it is larger than the sum of its proper divisors (11683599).

21997041 is a wasteful number, since it uses less digits than its factorization.

21997041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35116.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 21997041 is about 4690.1003187565. The cubic root of 21997041 is about 280.1913700259.

The spelling of 21997041 in words is "twenty-one million, nine hundred ninety-seven thousand, forty-one".