63721644 has 48 divisors (see below), whose sum is σ = 179923968. Its totient is φ = 17134848.

The previous prime is 63721639. The next prime is 63721663. The reversal of 63721644 is 44612736.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20884 + ... + 23739.

It is an arithmetic number, because the mean of its divisors is an integer number (3748416).

Almost surely, 2^63721644 is an apocalyptic number.

It is an amenable number.

63721644 is an abundant number, since it is smaller than the sum of its proper divisors (116202324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

63721644 is a wasteful number, since it uses less digits than its factorization.

63721644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44654 (or 44652 counting only the distinct ones).

The product of its digits is 24192, while the sum is 33.

The square root of 63721644 is about 7982.5837922317. The cubic root of 63721644 is about 399.4192488951.

The spelling of 63721644 in words is "sixty-three million, seven hundred twenty-one thousand, six hundred forty-four".