667181477 has 2 divisors, whose sum is σ = 667181478. Its totient is φ = 667181476.

The previous prime is 667181441. The next prime is 667181483. The reversal of 667181477 is 774181766.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639027841 + 28153636 = 25279^2 + 5306^2 .

It is a cyclic number.

It is not a de Polignac number, because 667181477 - 2⁶ = 667181413 is a prime.

It is a super-2 number, since 2×667181477² = 890262246503803058, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667181407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333590738 + 333590739.

It is an arithmetic number, because the mean of its divisors is an integer number (333590739).

Almost surely, 2^667181477 is an apocalyptic number.

It is an amenable number.

667181477 is a deficient number, since it is larger than the sum of its proper divisors (1).

667181477 is an equidigital number, since it uses as much as digits as its factorization.

667181477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 395136, while the sum is 47.

The square root of 667181477 is about 25829.8563100920. The cubic root of 667181477 is about 873.8052710051.

The spelling of 667181477 in words is "six hundred sixty-seven million, one hundred eighty-one thousand, four hundred seventy-seven".