137721967 has 4 divisors (see below), whose sum is σ = 137754736. Its totient is φ = 137689200.

The previous prime is 137721923. The next prime is 137721971. The reversal of 137721967 is 769127731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 769127731 = 10159 ⋅75709.

It is a cyclic number.

It is not a de Polignac number, because 137721967 - 2¹¹ = 137719919 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 (137721167) 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, 8958 + ... + 18859.

It is an arithmetic number, because the mean of its divisors is an integer number (34438684).

Almost surely, 2^137721967 is an apocalyptic number.

137721967 is a deficient number, since it is larger than the sum of its proper divisors (32769).

137721967 is an equidigital number, since it uses as much as digits as its factorization.

137721967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32768.

The product of its digits is 111132, while the sum is 43.

The square root of 137721967 is about 11735.5002875889. The cubic root of 137721967 is about 516.4176443154.

The spelling of 137721967 in words is "one hundred thirty-seven million, seven hundred twenty-one thousand, nine hundred sixty-seven".