21530023141 has 4 divisors (see below), whose sum is σ = 23487297984. Its totient is φ = 19572748300.

The previous prime is 21530023121. The next prime is 21530023157. The reversal of 21530023141 is 14132003512.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 21530023141 - 2²¹ = 21527925989 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 (21530023111) 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, 978637405 + ... + 978637426.

It is an arithmetic number, because the mean of its divisors is an integer number (5871824496).

Almost surely, 2^21530023141 is an apocalyptic number.

It is an amenable number.

21530023141 is a deficient number, since it is larger than the sum of its proper divisors (1957274843).

21530023141 is a wasteful number, since it uses less digits than its factorization.

21530023141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1957274842.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21530023141 its reverse (14132003512), we get a palindrome (35662026653).

The spelling of 21530023141 in words is "twenty-one billion, five hundred thirty million, twenty-three thousand, one hundred forty-one".