666733401 has 12 divisors (see below), whose sum is σ = 963283620. Its totient is φ = 444385440.

The previous prime is 666733393. The next prime is 666733409. The reversal of 666733401 is 104337666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (666733393) and next prime (666733409).

It can be written as a sum of positive squares in 2 ways, for example, as 147987225 + 518746176 = 12165^2 + 22776^2 .

It is not a de Polignac number, because 666733401 - 2³ = 666733393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666733409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68031 + ... + 77211.

It is an arithmetic number, because the mean of its divisors is an integer number (80273635).

Almost surely, 2^666733401 is an apocalyptic number.

It is an amenable number.

666733401 is a deficient number, since it is larger than the sum of its proper divisors (296550219).

666733401 is a wasteful number, since it uses less digits than its factorization.

666733401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17256 (or 17253 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

The square root of 666733401 is about 25821.1812471854. The cubic root of 666733401 is about 873.6096126687.

The spelling of 666733401 in words is "six hundred sixty-six million, seven hundred thirty-three thousand, four hundred one".