65015551 has 4 divisors (see below), whose sum is σ = 65071512. Its totient is φ = 64959592.

The previous prime is 65015537. The next prime is 65015563. The reversal of 65015551 is 15551056.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65015551 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 (65015521) 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, 26200 + ... + 28573.

It is an arithmetic number, because the mean of its divisors is an integer number (16267878).

Almost surely, 2^65015551 is an apocalyptic number.

65015551 is a deficient number, since it is larger than the sum of its proper divisors (55961).

65015551 is a wasteful number, since it uses less digits than its factorization.

65015551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55960.

The product of its (nonzero) digits is 3750, while the sum is 28.

The square root of 65015551 is about 8063.2221227001. Note that the first 3 decimals coincide. The cubic root of 65015551 is about 402.1046380746.

The spelling of 65015551 in words is "sixty-five million, fifteen thousand, five hundred fifty-one".