21550741 has 4 divisors (see below), whose sum is σ = 22293900. Its totient is φ = 20807584.

The previous prime is 21550691. The next prime is 21550777. The reversal of 21550741 is 14705512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15444900 + 6105841 = 3930^2 + 2471^2 .

It is a cyclic number.

It is not a de Polignac number, because 21550741 - 2⁹ = 21550229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500741) 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, 371536 + ... + 371593.

It is an arithmetic number, because the mean of its divisors is an integer number (5573475).

Almost surely, 2^21550741 is an apocalyptic number.

It is an amenable number.

21550741 is a deficient number, since it is larger than the sum of its proper divisors (743159).

21550741 is an equidigital number, since it uses as much as digits as its factorization.

21550741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743158.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 21550741 is about 4642.2775660230. The cubic root of 21550741 is about 278.2834651555.

The spelling of 21550741 in words is "twenty-one million, five hundred fifty thousand, seven hundred forty-one".