1373511981 has 4 divisors (see below), whose sum is σ = 1831349312. Its totient is φ = 915674652.

The previous prime is 1373511961. The next prime is 1373511989. The reversal of 1373511981 is 1891153731.

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.

It is not a de Polignac number, because 1373511981 - 2¹⁴ = 1373495597 is a prime.

It is a super-2 number, since 2×1373511981² = 3773070323901088722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1373511989) 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, 228918661 + ... + 228918666.

It is an arithmetic number, because the mean of its divisors is an integer number (457837328).

Almost surely, 2^1373511981 is an apocalyptic number.

It is an amenable number.

1373511981 is a deficient number, since it is larger than the sum of its proper divisors (457837331).

1373511981 is an equidigital number, since it uses as much as digits as its factorization.

1373511981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457837330.

The product of its digits is 22680, while the sum is 39.

The square root of 1373511981 is about 37060.9225600227. The cubic root of 1373511981 is about 1111.5887702389.

The spelling of 1373511981 in words is "one billion, three hundred seventy-three million, five hundred eleven thousand, nine hundred eighty-one".