156993457 has 2 divisors, whose sum is σ = 156993458. Its totient is φ = 156993456.

The previous prime is 156993391. The next prime is 156993467. The reversal of 156993457 is 754399651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152868496 + 4124961 = 12364^2 + 2031^2 .

It is an emirp because it is prime and its reverse (754399651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 156993457 - 2⁷ = 156993329 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 156993457.

It is not a weakly prime, because it can be changed into another prime (156993467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78496728 + 78496729.

It is an arithmetic number, because the mean of its divisors is an integer number (78496729).

Almost surely, 2^156993457 is an apocalyptic number.

It is an amenable number.

156993457 is a deficient number, since it is larger than the sum of its proper divisors (1).

156993457 is an equidigital number, since it uses as much as digits as its factorization.

156993457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1020600, while the sum is 49.

The square root of 156993457 is about 12529.7029892971. The cubic root of 156993457 is about 539.4615769537.

The spelling of 156993457 in words is "one hundred fifty-six million, nine hundred ninety-three thousand, four hundred fifty-seven".