156673661 has 2 divisors, whose sum is σ = 156673662. Its totient is φ = 156673660.

The previous prime is 156673633. The next prime is 156673667. The reversal of 156673661 is 166376651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114618436 + 42055225 = 10706^2 + 6485^2 .

It is a cyclic number.

It is not a de Polignac number, because 156673661 - 2¹⁸ = 156411517 is a prime.

It is a super-2 number, since 2×156673661² = 49093272102285842, which contains 22 as substring.

It is a Chen prime.

It is equal to p_8798342 and since 156673661 and 8798342 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156673667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78336830 + 78336831.

It is an arithmetic number, because the mean of its divisors is an integer number (78336831).

Almost surely, 2^156673661 is an apocalyptic number.

It is an amenable number.

156673661 is a deficient number, since it is larger than the sum of its proper divisors (1).

156673661 is an equidigital number, since it uses as much as digits as its factorization.

156673661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 41.

The square root of 156673661 is about 12516.9349682740. The cubic root of 156673661 is about 539.0950331709.

The spelling of 156673661 in words is "one hundred fifty-six million, six hundred seventy-three thousand, six hundred sixty-one".