21463444537 has 4 divisors (see below), whose sum is σ = 22726000116. Its totient is φ = 20200888960.

The previous prime is 21463444489. The next prime is 21463444553. The reversal of 21463444537 is 73544436412.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11946271401 + 9517173136 = 109299^2 + 97556^2 .

It is a cyclic number.

It is not a de Polignac number, because 21463444537 - 2¹⁹ = 21462920249 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21463444493 and 21463444502.

It is not an unprimeable number, because it can be changed into a prime (21463444577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 631277764 + ... + 631277797.

It is an arithmetic number, because the mean of its divisors is an integer number (5681500029).

Almost surely, 2^21463444537 is an apocalyptic number.

It is an amenable number.

21463444537 is a deficient number, since it is larger than the sum of its proper divisors (1262555579).

21463444537 is a wasteful number, since it uses less digits than its factorization.

21463444537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262555578.

The product of its digits is 967680, while the sum is 43.

The spelling of 21463444537 in words is "twenty-one billion, four hundred sixty-three million, four hundred forty-four thousand, five hundred thirty-seven".