6621541563 has 16 divisors (see below), whose sum is σ = 10866119936. Its totient is φ = 3492681120.

The previous prime is 6621541559. The next prime is 6621541567. The reversal of 6621541563 is 3651451266.

It is an interprime number because it is at equal distance from previous prime (6621541559) and next prime (6621541567).

It is not a de Polignac number, because 6621541563 - 2² = 6621541559 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (6621541567) 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, 12127093 + ... + 12127638.

It is an arithmetic number, because the mean of its divisors is an integer number (679132496).

Almost surely, 2^6621541563 is an apocalyptic number.

6621541563 is a deficient number, since it is larger than the sum of its proper divisors (4244578373).

6621541563 is a wasteful number, since it uses less digits than its factorization.

6621541563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24254754.

The product of its digits is 129600, while the sum is 39.

The square root of 6621541563 is about 81372.8551975412. The cubic root of 6621541563 is about 1877.8160056935.

The spelling of 6621541563 in words is "six billion, six hundred twenty-one million, five hundred forty-one thousand, five hundred sixty-three".