63721540 has 24 divisors (see below), whose sum is σ = 134409240. Its totient is φ = 25375488.

The previous prime is 63721517. The next prime is 63721543. The reversal of 63721540 is 4512736.

It can be written as a sum of positive squares in 4 ways, for example, as 23677956 + 40043584 = 4866^2 + 6328^2 .

It is a junction number, because it is equal to n+sod(n) for n = 63721499 and 63721508.

It is not an unprimeable number, because it can be changed into a prime (63721543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2377 + ... + 11536.

It is an arithmetic number, because the mean of its divisors is an integer number (5600385).

Almost surely, 2^63721540 is an apocalyptic number.

It is an amenable number.

63721540 is an abundant number, since it is smaller than the sum of its proper divisors (70687700).

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

63721540 is a wasteful number, since it uses less digits than its factorization.

63721540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14151 (or 14149 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 63721540 is about 7982.5772780475. The cubic root of 63721540 is about 399.4190315978.

It can be divided in two parts, 63721 and 540, that added together give a triangular number (64261 = T₃₅₈).

The spelling of 63721540 in words is "sixty-three million, seven hundred twenty-one thousand, five hundred forty".