165620137 has 16 divisors (see below), whose sum is σ = 178749072. Its totient is φ = 152893440.

The previous prime is 165620129. The next prime is 165620141. The reversal of 165620137 is 731026561.

It can be written as a sum of positive squares in 8 ways, for example, as 31315216 + 134304921 = 5596^2 + 11589^2 .

It is a cyclic number.

It is not a de Polignac number, because 165620137 - 2³ = 165620129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165620099 and 165620108.

It is not an unprimeable number, because it can be changed into a prime (165620167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 393187 + ... + 393607.

It is an arithmetic number, because the mean of its divisors is an integer number (11171817).

Almost surely, 2^165620137 is an apocalyptic number.

165620137 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

165620137 is a deficient number, since it is larger than the sum of its proper divisors (13128935).

165620137 is a wasteful number, since it uses less digits than its factorization.

165620137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 165620137 is about 12869.3487403209. The cubic root of 165620137 is about 549.1669338617.

Adding to 165620137 its reverse (731026561), we get a palindrome (896646698).

The spelling of 165620137 in words is "one hundred sixty-five million, six hundred twenty thousand, one hundred thirty-seven".