137721243 has 8 divisors (see below), whose sum is σ = 200321856. Its totient is φ = 83467400.

The previous prime is 137721239. The next prime is 137721257. The reversal of 137721243 is 342127731.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 137721243 - 2² = 137721239 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 137721243.

It is not an unprimeable number, because it can be changed into a prime (137721293) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2086653 + ... + 2086718.

It is an arithmetic number, because the mean of its divisors is an integer number (25040232).

Almost surely, 2^137721243 is an apocalyptic number.

137721243 is a deficient number, since it is larger than the sum of its proper divisors (62600613).

137721243 is a wasteful number, since it uses less digits than its factorization.

137721243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4173385.

The product of its digits is 7056, while the sum is 30.

The square root of 137721243 is about 11735.4694409725. The cubic root of 137721243 is about 516.4167393834.

Adding to 137721243 its reverse (342127731), we get a palindrome (479848974).

The spelling of 137721243 in words is "one hundred thirty-seven million, seven hundred twenty-one thousand, two hundred forty-three".