157721077 has 2 divisors, whose sum is σ = 157721078. Its totient is φ = 157721076.

The previous prime is 157721041. The next prime is 157721089. The reversal of 157721077 is 770127751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147646801 + 10074276 = 12151^2 + 3174^2 .

It is an emirp because it is prime and its reverse (770127751) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 157721077 - 2⁷ = 157720949 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157721027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78860538 + 78860539.

It is an arithmetic number, because the mean of its divisors is an integer number (78860539).

Almost surely, 2^157721077 is an apocalyptic number.

It is an amenable number.

157721077 is a deficient number, since it is larger than the sum of its proper divisors (1).

157721077 is an equidigital number, since it uses as much as digits as its factorization.

157721077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24010, while the sum is 37.

The square root of 157721077 is about 12558.7052278489. The cubic root of 157721077 is about 540.2937096762.

The spelling of 157721077 in words is "one hundred fifty-seven million, seven hundred twenty-one thousand, seventy-seven".