67221520 has 20 divisors (see below), whose sum is σ = 156290220. Its totient is φ = 26888576.

The previous prime is 67221493. The next prime is 67221521. The reversal of 67221520 is 2512276.

It can be written as a sum of positive squares in 2 ways, for example, as 19501056 + 47720464 = 4416^2 + 6908^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×67221520² = 9037465502220800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (67221521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 420055 + ... + 420214.

It is an arithmetic number, because the mean of its divisors is an integer number (7814511).

Almost surely, 2^67221520 is an apocalyptic number.

It is an amenable number.

67221520 is an abundant number, since it is smaller than the sum of its proper divisors (89068700).

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

67221520 is a wasteful number, since it uses less digits than its factorization.

67221520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840282 (or 840276 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 67221520 is about 8198.8730932976. The cubic root of 67221520 is about 406.6019366053.

Adding to 67221520 its reverse (2512276), we get a palindrome (69733796).

The spelling of 67221520 in words is "sixty-seven million, two hundred twenty-one thousand, five hundred twenty".