146666721 has 4 divisors (see below), whose sum is σ = 195555632. Its totient is φ = 97777812.

The previous prime is 146666711. The next prime is 146666761. The reversal of 146666721 is 127666641.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 146666721 - 2¹⁰ = 146665697 is a prime.

It is a super-2 number, since 2×146666721² = 43022254097783682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 146666721.

It is not an unprimeable number, because it can be changed into a prime (146666711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24444451 + ... + 24444456.

It is an arithmetic number, because the mean of its divisors is an integer number (48888908).

Almost surely, 2^146666721 is an apocalyptic number.

It is an amenable number.

146666721 is a deficient number, since it is larger than the sum of its proper divisors (48888911).

146666721 is an equidigital number, since it uses as much as digits as its factorization.

146666721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48888910.

The product of its digits is 72576, while the sum is 39.

The square root of 146666721 is about 12110.6036596034. The cubic root of 146666721 is about 527.3640580191.

The spelling of 146666721 in words is "one hundred forty-six million, six hundred sixty-six thousand, seven hundred twenty-one".