109687561 has 2 divisors, whose sum is σ = 109687562. Its totient is φ = 109687560.

The previous prime is 109687547. The next prime is 109687603. The reversal of 109687561 is 165786901.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97219600 + 12467961 = 9860^2 + 3531^2 .

It is a cyclic number.

It is not a de Polignac number, because 109687561 - 2¹⁵ = 109654793 is a prime.

It is a super-2 number, since 2×109687561² = 24062722076257442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (109687511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54843780 + 54843781.

It is an arithmetic number, because the mean of its divisors is an integer number (54843781).

Almost surely, 2^109687561 is an apocalyptic number.

It is an amenable number.

109687561 is a deficient number, since it is larger than the sum of its proper divisors (1).

109687561 is an equidigital number, since it uses as much as digits as its factorization.

109687561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 109687561 is about 10473.1829450268. The cubic root of 109687561 is about 478.6879111513.

The spelling of 109687561 in words is "one hundred nine million, six hundred eighty-seven thousand, five hundred sixty-one".