155516761 has 2 divisors, whose sum is σ = 155516762. Its totient is φ = 155516760.

The previous prime is 155516759. The next prime is 155516797. The reversal of 155516761 is 167615551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147987225 + 7529536 = 12165^2 + 2744^2 .

It is an emirp because it is prime and its reverse (167615551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155516761 - 2¹ = 155516759 is a prime.

It is a super-2 number, since 2×155516761² = 48370925903862242, which contains 22 as substring.

Together with 155516759, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 155516761.

It is not a weakly prime, because it can be changed into another prime (155516741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77758380 + 77758381.

It is an arithmetic number, because the mean of its divisors is an integer number (77758381).

Almost surely, 2^155516761 is an apocalyptic number.

It is an amenable number.

155516761 is a deficient number, since it is larger than the sum of its proper divisors (1).

155516761 is an equidigital number, since it uses as much as digits as its factorization.

155516761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31500, while the sum is 37.

The square root of 155516761 is about 12470.6359501029. The cubic root of 155516761 is about 537.7648362096.

The spelling of 155516761 in words is "one hundred fifty-five million, five hundred sixteen thousand, seven hundred sixty-one".