65691649 has 4 divisors (see below), whose sum is σ = 66329536. Its totient is φ = 65053764.

The previous prime is 65691631. The next prime is 65691667. The reversal of 65691649 is 94619656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (65691631) and next prime (65691667).

It is a cyclic number.

It is not a de Polignac number, because 65691649 - 2⁵ = 65691617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 65691599 and 65691608.

It is not an unprimeable number, because it can be changed into a prime (65691629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 318789 + ... + 318994.

It is an arithmetic number, because the mean of its divisors is an integer number (16582384).

It is a Proth number, since it is equal to 8019 ⋅ 2¹³ + 1 and 8019 < 2¹³.

Almost surely, 2^65691649 is an apocalyptic number.

It is an amenable number.

65691649 is a deficient number, since it is larger than the sum of its proper divisors (637887).

65691649 is a wasteful number, since it uses less digits than its factorization.

65691649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637886.

The product of its digits is 349920, while the sum is 46.

The square root of 65691649 is about 8105.0384946649. The cubic root of 65691649 is about 403.4936656618.

The spelling of 65691649 in words is "sixty-five million, six hundred ninety-one thousand, six hundred forty-nine".