21530152015 has 8 divisors (see below), whose sum is σ = 26727085440. Its totient is φ = 16630186272.

The previous prime is 21530152013. The next prime is 21530152057. The reversal of 21530152015 is 51025103512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21530152015 - 2¹ = 21530152013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530152013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74241759 + ... + 74242048.

It is an arithmetic number, because the mean of its divisors is an integer number (3340885680).

Almost surely, 2^21530152015 is an apocalyptic number.

21530152015 is a deficient number, since it is larger than the sum of its proper divisors (5196933425).

21530152015 is a wasteful number, since it uses less digits than its factorization.

21530152015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148483841.

The product of its (nonzero) digits is 1500, while the sum is 25.

Adding to 21530152015 its reverse (51025103512), we get a palindrome (72555255527).

The spelling of 21530152015 in words is "twenty-one billion, five hundred thirty million, one hundred fifty-two thousand, fifteen".