109781615 has 4 divisors (see below), whose sum is σ = 131737944. Its totient is φ = 87825288.

The previous prime is 109781611. The next prime is 109781653. The reversal of 109781615 is 516187901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 516187901 = 317 ⋅1628353.

It is a cyclic number.

It is not a de Polignac number, because 109781615 - 2² = 109781611 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109781611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10978157 + ... + 10978166.

It is an arithmetic number, because the mean of its divisors is an integer number (32934486).

Almost surely, 2^109781615 is an apocalyptic number.

109781615 is a deficient number, since it is larger than the sum of its proper divisors (21956329).

109781615 is an equidigital number, since it uses as much as digits as its factorization.

109781615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21956328.

The product of its (nonzero) digits is 15120, while the sum is 38.

The square root of 109781615 is about 10477.6722128534. The cubic root of 109781615 is about 478.8246925390.

The spelling of 109781615 in words is "one hundred nine million, seven hundred eighty-one thousand, six hundred fifteen".