137213561 has 4 divisors (see below), whose sum is σ = 143179392. Its totient is φ = 131247732.

The previous prime is 137213551. The next prime is 137213597. The reversal of 137213561 is 165312731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165312731 = 29 ⋅5700439.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137213561 is a prime.

It is a super-2 number, since 2×137213561² = 37655122644601442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (137213551) 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, 2982881 + ... + 2982926.

It is an arithmetic number, because the mean of its divisors is an integer number (35794848).

Almost surely, 2^137213561 is an apocalyptic number.

It is an amenable number.

137213561 is a deficient number, since it is larger than the sum of its proper divisors (5965831).

137213561 is an equidigital number, since it uses as much as digits as its factorization.

137213561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5965830.

The product of its digits is 3780, while the sum is 29.

The square root of 137213561 is about 11713.8192320011. The cubic root of 137213561 is about 515.7814021584.

The spelling of 137213561 in words is "one hundred thirty-seven million, two hundred thirteen thousand, five hundred sixty-one".