66651516 has 72 divisors (see below), whose sum is σ = 177768864. Its totient is φ = 21014400.

The previous prime is 66651511. The next prime is 66651521. The reversal of 66651516 is 61515666.

It is an interprime number because it is at equal distance from previous prime (66651511) and next prime (66651521).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66651511) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 83230 + ... + 84026.

It is an arithmetic number, because the mean of its divisors is an integer number (2469012).

Almost surely, 2^66651516 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 66651516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88884432).

66651516 is an abundant number, since it is smaller than the sum of its proper divisors (111117348).

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

66651516 is a wasteful number, since it uses less digits than its factorization.

66651516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931 (or 926 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 66651516 is about 8164.0379714943. The cubic root of 66651516 is about 405.4494142394.

The spelling of 66651516 in words is "sixty-six million, six hundred fifty-one thousand, five hundred sixteen".