65501621 has 4 divisors (see below), whose sum is σ = 65687532. Its totient is φ = 65315712.

The previous prime is 65501603. The next prime is 65501651. The reversal of 65501621 is 12610556.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37039396 + 28462225 = 6086^2 + 5335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65501621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65501651) 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, 92426 + ... + 93131.

It is an arithmetic number, because the mean of its divisors is an integer number (16421883).

Almost surely, 2^65501621 is an apocalyptic number.

It is an amenable number.

65501621 is a deficient number, since it is larger than the sum of its proper divisors (185911).

65501621 is a wasteful number, since it uses less digits than its factorization.

65501621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185910.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 65501621 is about 8093.3071732142. The cubic root of 65501621 is about 403.1042242443.

The spelling of 65501621 in words is "sixty-five million, five hundred one thousand, six hundred twenty-one".