21507532021127 has 4 divisors (see below), whose sum is σ = 22639507390680. Its totient is φ = 20375556651576.

The previous prime is 21507532021121. The next prime is 21507532021133. The reversal of 21507532021127 is 72112023570512.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (21507532021121) and next prime (21507532021133).

It is not a de Polignac number, because 21507532021127 - 2⁴ = 21507532021111 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 (21507532021121) 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, 565987684748 + ... + 565987684785.

It is an arithmetic number, because the mean of its divisors is an integer number (5659876847670).

Almost surely, 2^{21507532021127} is an apocalyptic number.

21507532021127 is a deficient number, since it is larger than the sum of its proper divisors (1131975369553).

21507532021127 is a wasteful number, since it uses less digits than its factorization.

21507532021127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131975369552.

The product of its (nonzero) digits is 58800, while the sum is 38.

Adding to 21507532021127 its reverse (72112023570512), we get a palindrome (93619555591639).

The spelling of 21507532021127 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-two million, twenty-one thousand, one hundred twenty-seven".