63553621 has 4 divisors (see below), whose sum is σ = 63572032. Its totient is φ = 63535212.

The previous prime is 63553603. The next prime is 63553631. The reversal of 63553621 is 12635536.

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 3-Lehmer number, since φ(63553621) divides (63553621-1)³.

It is a cyclic number.

It is not a de Polignac number, because 63553621 - 2¹³ = 63545429 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 (63553631) 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, 2301 + ... + 11506.

It is an arithmetic number, because the mean of its divisors is an integer number (15893008).

Almost surely, 2^63553621 is an apocalyptic number.

63553621 is the 4603-rd octagonal number.

It is an amenable number.

63553621 is a deficient number, since it is larger than the sum of its proper divisors (18411).

63553621 is a wasteful number, since it uses less digits than its factorization.

63553621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18410.

The product of its digits is 16200, while the sum is 31.

The square root of 63553621 is about 7972.0524960640. The cubic root of 63553621 is about 399.0678732867.

The spelling of 63553621 in words is "sixty-three million, five hundred fifty-three thousand, six hundred twenty-one".