75224207429721 has 27 divisors (see below), whose sum is σ = 126397443694431. Its totient is φ = 42985157310144.

The previous prime is 75224207429711. The next prime is 75224207429747. The reversal of 75224207429721 is 12792470242257.

The square root of 75224207429721 is 8673189.

It is a perfect power (a square), and thus also a powerful number.

75224207429721 is a `hidden beast` number, since 7 + 5 + 2 + 2 + 4 + 207 + 429 + 7 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3814947269721 + 71409260160000 = 1953189^2 + 8450400^2 .

It is not a de Polignac number, because 75224207429721 - 2⁷ = 75224207429593 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (75224207429711) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 181930465 + ... + 182343473.

Almost surely, 2^{75224207429721} is an apocalyptic number.

75224207429721 is the 8673189-th square number.

75224207429721 is the 4336595-th centered octagonal number.

It is an amenable number.

75224207429721 is a deficient number, since it is larger than the sum of its proper divisors (51173236264710).

75224207429721 is an frugal number, since it uses more digits than its factorization.

75224207429721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826038 (or 413019 counting only the distinct ones).

The product of its (nonzero) digits is 7902720, while the sum is 54.

The spelling of 75224207429721 in words is "seventy-five trillion, two hundred twenty-four billion, two hundred seven million, four hundred twenty-nine thousand, seven hundred twenty-one".