66400736 has 12 divisors (see below), whose sum is σ = 130726512. Its totient is φ = 33200352.

The previous prime is 66400661. The next prime is 66400751. The reversal of 66400736 is 63700466.

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 2075023 = 66400736 / (6 + 6 + 4 + 0 + 0 + 7 + 3 + 6).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1037480 + ... + 1037543.

It is an arithmetic number, because the mean of its divisors is an integer number (10893876).

Almost surely, 2^66400736 is an apocalyptic number.

It is an amenable number.

66400736 is a deficient number, since it is larger than the sum of its proper divisors (64325776).

66400736 is a wasteful number, since it uses less digits than its factorization.

66400736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2075033 (or 2075025 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 32.

The square root of 66400736 is about 8148.6646758840. The cubic root of 66400736 is about 404.9402665549.

The spelling of 66400736 in words is "sixty-six million, four hundred thousand, seven hundred thirty-six".