66421512 has 64 divisors (see below), whose sum is σ = 189513600. Its totient is φ = 21539520.

The previous prime is 66421489. The next prime is 66421547. The reversal of 66421512 is 21512466.

66421512 is a `hidden beast` number, since 6 + 642 + 1 + 5 + 12 = 666.

It is a super-2 number, since 2×66421512² = 8823634512732288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3837 + ... + 12147.

It is an arithmetic number, because the mean of its divisors is an integer number (2961150).

Almost surely, 2^66421512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66421512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94756800).

66421512 is an abundant number, since it is smaller than the sum of its proper divisors (123092088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66421512 is a wasteful number, since it uses less digits than its factorization.

66421512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8363 (or 8353 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 66421512 is about 8149.9393862777. The cubic root of 66421512 is about 404.9824958141.

Adding to 66421512 its reverse (21512466), we get a palindrome (87933978).

The spelling of 66421512 in words is "sixty-six million, four hundred twenty-one thousand, five hundred twelve".