21148562387 has 4 divisors (see below), whose sum is σ = 21547591920. Its totient is φ = 20749532856.

The previous prime is 21148562363. The next prime is 21148562443. The reversal of 21148562387 is 78326584112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21148562387 is a prime.

It is a super-2 number, since 2×21148562387² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21148562087) 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, 199514687 + ... + 199514792.

It is an arithmetic number, because the mean of its divisors is an integer number (5386897980).

Almost surely, 2^21148562387 is an apocalyptic number.

21148562387 is a deficient number, since it is larger than the sum of its proper divisors (399029533).

21148562387 is an equidigital number, since it uses as much as digits as its factorization.

21148562387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399029532.

The product of its digits is 645120, while the sum is 47.

The spelling of 21148562387 in words is "twenty-one billion, one hundred forty-eight million, five hundred sixty-two thousand, three hundred eighty-seven".