65942640 has 80 divisors (see below), whose sum is σ = 227143200. Its totient is φ = 17584128.

The previous prime is 65942627. The next prime is 65942641. The reversal of 65942640 is 4624956.

65942640 is a `hidden beast` number, since 6 + 5 + 9 + 4 + 2 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a junction number, because it is equal to n+sod(n) for n = 65942595 and 65942604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65942641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13105 + ... + 17424.

It is an arithmetic number, because the mean of its divisors is an integer number (2839290).

Almost surely, 2^65942640 is an apocalyptic number.

65942640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

65942640 is an abundant number, since it is smaller than the sum of its proper divisors (161200560).

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

65942640 is a wasteful number, since it uses less digits than its factorization.

65942640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30551 (or 30539 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 65942640 is about 8120.5073733111. The cubic root of 65942640 is about 404.0068946312.

The spelling of 65942640 in words is "sixty-five million, nine hundred forty-two thousand, six hundred forty".