65540391 has 12 divisors (see below), whose sum is σ = 101654712. Its totient is φ = 37451568.

The previous prime is 65540353. The next prime is 65540393. The reversal of 65540391 is 19304556.

It is a happy number.

It is not a de Polignac number, because 65540391 - 2¹⁴ = 65524007 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65540393) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 222780 + ... + 223073.

It is an arithmetic number, because the mean of its divisors is an integer number (8471226).

Almost surely, 2^65540391 is an apocalyptic number.

65540391 is a deficient number, since it is larger than the sum of its proper divisors (36114321).

65540391 is a wasteful number, since it uses less digits than its factorization.

65540391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445870 (or 445863 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 33.

The square root of 65540391 is about 8095.7020078558. The cubic root of 65540391 is about 403.1837401815.

The spelling of 65540391 in words is "sixty-five million, five hundred forty thousand, three hundred ninety-one".