67721522 has 30 divisors (see below), whose sum is σ = 116731839. Its totient is φ = 29444140.

The previous prime is 67721519. The next prime is 67721527. The reversal of 67721522 is 22512776.

It can be written as a sum of positive squares in only one way, i.e., 33860761 + 33860761 = 5819^2 + 5819^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=5819.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67721527) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2944403 + ... + 2944425.

Almost surely, 2^67721522 is an apocalyptic number.

67721522 is a deficient number, since it is larger than the sum of its proper divisors (49010317).

67721522 is an frugal number, since it uses more digits than its factorization.

67721522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 36 counting only the distinct ones).

The product of its digits is 11760, while the sum is 32.

The square root of 67721522 is about 8229.3087194490. The cubic root of 67721522 is about 407.6075659180.

Multiplying 67721522 by its sum of digits (32), we get a square (2167088704 = 46552²).

The spelling of 67721522 in words is "sixty-seven million, seven hundred twenty-one thousand, five hundred twenty-two".