66990924 has 216 divisors, whose sum is σ = 230441120. Its totient is φ = 16061760.

The previous prime is 66990919. The next prime is 66990943. The reversal of 66990924 is 42909966.

66990924 = T₁₀ + T₁₁ + ... + T₇₃₇.

It is a self number, because there is not a number n which added to its sum of digits gives 66990924.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5153142 + ... + 5153154.

Almost surely, 2^66990924 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 66990924, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115220560).

66990924 is an abundant number, since it is smaller than the sum of its proper divisors (163450196).

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

66990924 is a wasteful number, since it uses less digits than its factorization.

66990924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 66990924 is about 8184.7983481574. The cubic root of 66990924 is about 406.1364696092.

The spelling of 66990924 in words is "sixty-six million, nine hundred ninety thousand, nine hundred twenty-four".