66690432 has 128 divisors (see below), whose sum is σ = 205632000. Its totient is φ = 21238272.

The previous prime is 66690427. The next prime is 66690461. The reversal of 66690432 is 23409666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×66690432² = 8895227440693248, which contains 22 as substring.

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

It is a congruent number.

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, 79069 + ... + 79907.

It is an arithmetic number, because the mean of its divisors is an integer number (1606500).

Almost surely, 2^66690432 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 66690432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102816000).

66690432 is an abundant number, since it is smaller than the sum of its proper divisors (138941568).

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

66690432 is a wasteful number, since it uses less digits than its factorization.

66690432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 885 (or 867 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 66690432 is about 8166.4210031078. The cubic root of 66690432 is about 405.5283091667.

The spelling of 66690432 in words is "sixty-six million, six hundred ninety thousand, four hundred thirty-two".