163507681 has 2 divisors, whose sum is σ = 163507682. Its totient is φ = 163507680.

The previous prime is 163507637. The next prime is 163507693. The reversal of 163507681 is 186705361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153363456 + 10144225 = 12384^2 + 3185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-163507681 is a prime.

It is a super-2 number, since 2×163507681² = 53469523491995522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 163507681.

It is not a weakly prime, because it can be changed into another prime (163507381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81753840 + 81753841.

It is an arithmetic number, because the mean of its divisors is an integer number (81753841).

Almost surely, 2^163507681 is an apocalyptic number.

It is an amenable number.

163507681 is a deficient number, since it is larger than the sum of its proper divisors (1).

163507681 is an equidigital number, since it uses as much as digits as its factorization.

163507681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 163507681 is about 12787.0121998847. The cubic root of 163507681 is about 546.8220932154.

The spelling of 163507681 in words is "one hundred sixty-three million, five hundred seven thousand, six hundred eighty-one".