15515161665 has 32 divisors (see below), whose sum is σ = 25008586752. Its totient is φ = 8213400000.

The previous prime is 15515161663. The next prime is 15515161687. The reversal of 15515161665 is 56616151551.

It is not a de Polignac number, because 15515161665 - 2¹ = 15515161663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15515161663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4417260 + ... + 4420770.

It is an arithmetic number, because the mean of its divisors is an integer number (781518336).

Almost surely, 2^15515161665 is an apocalyptic number.

15515161665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

15515161665 is a deficient number, since it is larger than the sum of its proper divisors (9493425087).

15515161665 is a wasteful number, since it uses less digits than its factorization.

15515161665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5621.

The product of its digits is 135000, while the sum is 42.

The spelling of 15515161665 in words is "fifteen billion, five hundred fifteen million, one hundred sixty-one thousand, six hundred sixty-five".