65544721 has 8 divisors (see below), whose sum is σ = 71978688. Its totient is φ = 59190000.

The previous prime is 65544701. The next prime is 65544749. The reversal of 65544721 is 12744556.

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 65544721 - 2⁷ = 65544593 is a prime.

It is a super-2 number, since 2×65544721² = 8592220901935682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65544701) 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, 18070 + ... + 21391.

It is an arithmetic number, because the mean of its divisors is an integer number (8997336).

Almost surely, 2^65544721 is an apocalyptic number.

It is an amenable number.

65544721 is a deficient number, since it is larger than the sum of its proper divisors (6433967).

65544721 is a wasteful number, since it uses less digits than its factorization.

65544721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39623.

The product of its digits is 33600, while the sum is 34.

The square root of 65544721 is about 8095.9694292901. The cubic root of 65544721 is about 403.1926189158.

The spelling of 65544721 in words is "sixty-five million, five hundred forty-four thousand, seven hundred twenty-one".