65631421 has 4 divisors (see below), whose sum is σ = 65724700. Its totient is φ = 65538144.

The previous prime is 65631413. The next prime is 65631431. The reversal of 65631421 is 12413656.

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 6125625 + 59505796 = 2475^2 + 7714^2 .

It is a cyclic number.

It is not a de Polignac number, because 65631421 - 2³ = 65631413 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65631421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65631431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45576 + ... + 46993.

It is an arithmetic number, because the mean of its divisors is an integer number (16431175).

Almost surely, 2^65631421 is an apocalyptic number.

It is an amenable number.

65631421 is a deficient number, since it is larger than the sum of its proper divisors (93279).

65631421 is an equidigital number, since it uses as much as digits as its factorization.

65631421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93278.

The product of its digits is 4320, while the sum is 28.

The square root of 65631421 is about 8101.3221760402. The cubic root of 65631421 is about 403.3703164109.

The spelling of 65631421 in words is "sixty-five million, six hundred thirty-one thousand, four hundred twenty-one".