61663421 has 4 divisors (see below), whose sum is σ = 61909344. Its totient is φ = 61417500.

The previous prime is 61663409. The next prime is 61663451. The reversal of 61663421 is 12436616.

It is a happy number.

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 cyclic number.

It is not a de Polignac number, because 61663421 - 2¹⁰ = 61662397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61663451) 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, 122585 + ... + 123086.

It is an arithmetic number, because the mean of its divisors is an integer number (15477336).

Almost surely, 2^61663421 is an apocalyptic number.

It is an amenable number.

61663421 is a deficient number, since it is larger than the sum of its proper divisors (245923).

61663421 is a wasteful number, since it uses less digits than its factorization.

61663421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245922.

The product of its digits is 5184, while the sum is 29.

The square root of 61663421 is about 7852.6060005580. The cubic root of 61663421 is about 395.0716550026.

The spelling of 61663421 in words is "sixty-one million, six hundred sixty-three thousand, four hundred twenty-one".