667156397 has 12 divisors (see below), whose sum is σ = 698711580. Its totient is φ = 636201216.

The previous prime is 667156393. The next prime is 667156403. The reversal of 667156397 is 793651766.

It can be written as a sum of positive squares in 2 ways, for example, as 324684361 + 342472036 = 18019^2 + 18506^2 .

It is not a de Polignac number, because 667156397 - 2² = 667156393 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667156393) 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, 1369688 + ... + 1370174.

It is an arithmetic number, because the mean of its divisors is an integer number (58225965).

Almost surely, 2^667156397 is an apocalyptic number.

It is an amenable number.

667156397 is a deficient number, since it is larger than the sum of its proper divisors (31555183).

667156397 is an frugal number, since it uses more digits than its factorization.

667156397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1100 (or 613 counting only the distinct ones).

The product of its digits is 1428840, while the sum is 50.

The square root of 667156397 is about 25829.3708208311. The cubic root of 667156397 is about 873.7943218048.

The spelling of 667156397 in words is "six hundred sixty-seven million, one hundred fifty-six thousand, three hundred ninety-seven".