21507532044437 has 16 divisors (see below), whose sum is σ = 21687051672000. Its totient is φ = 21328250661120.

The previous prime is 21507532044409. The next prime is 21507532044491. The reversal of 21507532044437 is 73444023570512.

It is a cyclic number.

It is not a de Polignac number, because 21507532044437 - 2²⁶ = 21507464935573 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21507532044391 and 21507532044400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21507532044407) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1377003014 + ... + 1377018632.

It is an arithmetic number, because the mean of its divisors is an integer number (1355440729500).

Almost surely, 2^{21507532044437} is an apocalyptic number.

It is an amenable number.

21507532044437 is a deficient number, since it is larger than the sum of its proper divisors (179519627563).

21507532044437 is a wasteful number, since it uses less digits than its factorization.

21507532044437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22516.

The product of its (nonzero) digits is 2822400, while the sum is 47.

The spelling of 21507532044437 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-two million, forty-four thousand, four hundred thirty-seven".