66969870 has 96 divisors (see below), whose sum is σ = 186157440. Its totient is φ = 15364800.

The previous prime is 66969869. The next prime is 66969871. The reversal of 66969870 is 7896966.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66969869) and next prime (66969871).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66969871) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 68485 + ... + 69455.

It is an arithmetic number, because the mean of its divisors is an integer number (1939140).

Almost surely, 2^66969870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66969870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93078720).

66969870 is an abundant number, since it is smaller than the sum of its proper divisors (119187570).

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

66969870 is a wasteful number, since it uses less digits than its factorization.

66969870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1022 (or 1011 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 51.

The square root of 66969870 is about 8183.5120822297. The cubic root of 66969870 is about 406.0939181078.

The spelling of 66969870 in words is "sixty-six million, nine hundred sixty-nine thousand, eight hundred seventy".