65137721 has 8 divisors (see below), whose sum is σ = 71357088. Its totient is φ = 58968000.

The previous prime is 65137717. The next prime is 65137739. The reversal of 65137721 is 12773156.

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 65137721 - 2² = 65137717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (65137781) 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, 9635 + ... + 14936.

It is an arithmetic number, because the mean of its divisors is an integer number (8919636).

Almost surely, 2^65137721 is an apocalyptic number.

It is an amenable number.

65137721 is a deficient number, since it is larger than the sum of its proper divisors (6219367).

65137721 is a wasteful number, since it uses less digits than its factorization.

65137721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24823.

The product of its digits is 8820, while the sum is 32.

The square root of 65137721 is about 8070.7943227417. The cubic root of 65137721 is about 402.3563439347.

The spelling of 65137721 in words is "sixty-five million, one hundred thirty-seven thousand, seven hundred twenty-one".