21361537241 has 4 divisors (see below), whose sum is σ = 23303495184. Its totient is φ = 19419579300.

The previous prime is 21361537231. The next prime is 21361537273. The reversal of 21361537241 is 14273516312.

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 21361537241 - 2²⁶ = 21294428377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21361537231) 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, 970978955 + ... + 970978976.

It is an arithmetic number, because the mean of its divisors is an integer number (5825873796).

Almost surely, 2^21361537241 is an apocalyptic number.

It is an amenable number.

21361537241 is a deficient number, since it is larger than the sum of its proper divisors (1941957943).

21361537241 is a wasteful number, since it uses less digits than its factorization.

21361537241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1941957942.

The product of its digits is 30240, while the sum is 35.

The spelling of 21361537241 in words is "twenty-one billion, three hundred sixty-one million, five hundred thirty-seven thousand, two hundred forty-one".