75429721 has 2 divisors, whose sum is σ = 75429722. Its totient is φ = 75429720.

The previous prime is 75429701. The next prime is 75429743. The reversal of 75429721 is 12792457.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38887696 + 36542025 = 6236^2 + 6045^2 .

It is a cyclic number.

It is not a de Polignac number, because 75429721 - 2¹⁵ = 75396953 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (75429701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37714860 + 37714861.

It is an arithmetic number, because the mean of its divisors is an integer number (37714861).

Almost surely, 2^75429721 is an apocalyptic number.

It is an amenable number.

75429721 is a deficient number, since it is larger than the sum of its proper divisors (1).

75429721 is an equidigital number, since it uses as much as digits as its factorization.

75429721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 37.

The square root of 75429721 is about 8685.0285549329. The cubic root of 75429721 is about 422.5202231138.

The spelling of 75429721 in words is "seventy-five million, four hundred twenty-nine thousand, seven hundred twenty-one".