61663321 has 4 divisors (see below), whose sum is σ = 61704144. Its totient is φ = 61622500.

The previous prime is 61663313. The next prime is 61663331. The reversal of 61663321 is 12336616.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a 4-Lehmer number, since φ(61663321) divides (61663321-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 61663321 - 2³ = 61663313 is a prime.

It is a deceptive number, since it divides R_61663320.

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 61663321.

It is not an unprimeable number, because it can be changed into a prime (61663331) 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, 18055 + ... + 21196.

It is an arithmetic number, because the mean of its divisors is an integer number (15426036).

Almost surely, 2^61663321 is an apocalyptic number.

It is an amenable number.

61663321 is a deficient number, since it is larger than the sum of its proper divisors (40823).

61663321 is a wasteful number, since it uses less digits than its factorization.

61663321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40822.

The product of its digits is 3888, while the sum is 28.

The square root of 61663321 is about 7852.5996332425. The cubic root of 61663321 is about 395.0714414390.

Adding to 61663321 its reverse (12336616), we get a palindrome (73999937).

The spelling of 61663321 in words is "sixty-one million, six hundred sixty-three thousand, three hundred twenty-one".