65640637 has 8 divisors (see below), whose sum is σ = 66830400. Its totient is φ = 64457184.

The previous prime is 65640629. The next prime is 65640647. The reversal of 65640637 is 73604656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65640637 - 2³ = 65640629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 65640596 and 65640605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65640647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22689 + ... + 25417.

It is an arithmetic number, because the mean of its divisors is an integer number (8353800).

Almost surely, 2^65640637 is an apocalyptic number.

65640637 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

It is an amenable number.

65640637 is a deficient number, since it is larger than the sum of its proper divisors (1189763).

65640637 is a wasteful number, since it uses less digits than its factorization.

65640637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3155.

The product of its (nonzero) digits is 90720, while the sum is 37.

The square root of 65640637 is about 8101.8909521173. The cubic root of 65640637 is about 403.3891960206.

The spelling of 65640637 in words is "sixty-five million, six hundred forty thousand, six hundred thirty-seven".