63645216621 has 16 divisors (see below), whose sum is σ = 97037094528. Its totient is φ = 36348480000.

The previous prime is 63645216619. The next prime is 63645216629. The reversal of 63645216621 is 12661254636.

It is not a de Polignac number, because 63645216621 - 2¹ = 63645216619 is a prime.

It is a super-3 number, since 3×63645216621³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63645216629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 803580 + ... + 879221.

It is an arithmetic number, because the mean of its divisors is an integer number (6064818408).

Almost surely, 2^63645216621 is an apocalyptic number.

It is an amenable number.

63645216621 is a deficient number, since it is larger than the sum of its proper divisors (33391877907).

63645216621 is a wasteful number, since it uses less digits than its factorization.

63645216621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1684612.

The product of its digits is 311040, while the sum is 42.

The spelling of 63645216621 in words is "sixty-three billion, six hundred forty-five million, two hundred sixteen thousand, six hundred twenty-one".