65193721 has 2 divisors, whose sum is σ = 65193722. Its totient is φ = 65193720.

The previous prime is 65193697. The next prime is 65193743. The reversal of 65193721 is 12739156.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36421225 + 28772496 = 6035^2 + 5364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65193721 is a prime.

It is not a weakly prime, because it can be changed into another prime (65193221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32596860 + 32596861.

It is an arithmetic number, because the mean of its divisors is an integer number (32596861).

Almost surely, 2^65193721 is an apocalyptic number.

It is an amenable number.

65193721 is a deficient number, since it is larger than the sum of its proper divisors (1).

65193721 is an equidigital number, since it uses as much as digits as its factorization.

65193721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 34.

The square root of 65193721 is about 8074.2628765727. The cubic root of 65193721 is about 402.4716150913.

The spelling of 65193721 in words is "sixty-five million, one hundred ninety-three thousand, seven hundred twenty-one".