66767440 has 20 divisors (see below), whose sum is σ = 155234484. Its totient is φ = 26706944.

The previous prime is 66767431. The next prime is 66767453. The reversal of 66767440 is 4476766.

It can be written as a sum of positive squares in 2 ways, for example, as 51494976 + 15272464 = 7176^2 + 3908^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 66767393 and 66767402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 417217 + ... + 417376.

Almost surely, 2^66767440 is an apocalyptic number.

It is an amenable number.

66767440 is an abundant number, since it is smaller than the sum of its proper divisors (88467044).

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

66767440 is a wasteful number, since it uses less digits than its factorization.

66767440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834606 (or 834600 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 40.

The square root of 66767440 is about 8171.1345601452. The cubic root of 66767440 is about 405.6843381037.

The spelling of 66767440 in words is "sixty-six million, seven hundred sixty-seven thousand, four hundred forty".