66021563 has 2 divisors, whose sum is σ = 66021564. Its totient is φ = 66021562.

The previous prime is 66021559. The next prime is 66021583. The reversal of 66021563 is 36512066.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66021563 - 2² = 66021559 is a prime.

It is a super-3 number, since 3×66021563³ (a number of 24 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (66021503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33010781 + 33010782.

It is an arithmetic number, because the mean of its divisors is an integer number (33010782).

Almost surely, 2^66021563 is an apocalyptic number.

66021563 is a deficient number, since it is larger than the sum of its proper divisors (1).

66021563 is an equidigital number, since it uses as much as digits as its factorization.

66021563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 66021563 is about 8125.3654071679. The cubic root of 66021563 is about 404.1680080068.

The spelling of 66021563 in words is "sixty-six million, twenty-one thousand, five hundred sixty-three".