137220305 has 4 divisors (see below), whose sum is σ = 164664372. Its totient is φ = 109776240.

The previous prime is 137220301. The next prime is 137220329. The reversal of 137220305 is 503022731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 503022731 = 59 ⋅8525809.

It can be written as a sum of positive squares in 2 ways, for example, as 72063121 + 65157184 = 8489^2 + 8072^2 .

It is not a de Polignac number, because 137220305 - 2² = 137220301 is a prime.

It is a super-3 number, since 3×137220305³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (137220301) 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, 13722026 + ... + 13722035.

It is an arithmetic number, because the mean of its divisors is an integer number (41166093).

Almost surely, 2^137220305 is an apocalyptic number.

It is an amenable number.

137220305 is a deficient number, since it is larger than the sum of its proper divisors (27444067).

137220305 is an equidigital number, since it uses as much as digits as its factorization.

137220305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27444066.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 137220305 is about 11714.1070935859. The cubic root of 137220305 is about 515.7898521803.

The spelling of 137220305 in words is "one hundred thirty-seven million, two hundred twenty thousand, three hundred five".