21537741 has 4 divisors (see below), whose sum is σ = 28716992. Its totient is φ = 14358492.

The previous prime is 21537689. The next prime is 21537743. The reversal of 21537741 is 14773512.

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 not a de Polignac number, because 21537741 - 2⁷ = 21537613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21537699 and 21537708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537743) 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, 3589621 + ... + 3589626.

It is an arithmetic number, because the mean of its divisors is an integer number (7179248).

Almost surely, 2^21537741 is an apocalyptic number.

It is an amenable number.

21537741 is a deficient number, since it is larger than the sum of its proper divisors (7179251).

21537741 is an equidigital number, since it uses as much as digits as its factorization.

21537741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7179250.

The product of its digits is 5880, while the sum is 30.

The square root of 21537741 is about 4640.8771800167. The cubic root of 21537741 is about 278.2274978190.

The spelling of 21537741 in words is "twenty-one million, five hundred thirty-seven thousand, seven hundred forty-one".