1373137921 has 4 divisors (see below), whose sum is σ = 1373490112. Its totient is φ = 1372785732.

The previous prime is 1373137897. The next prime is 1373138027. The reversal of 1373137921 is 1297313731.

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 a cyclic number.

It is not a de Polignac number, because 1373137921 - 2²³ = 1364749313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1373137021) 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, 170181 + ... + 178066.

It is an arithmetic number, because the mean of its divisors is an integer number (343372528).

Almost surely, 2^1373137921 is an apocalyptic number.

It is an amenable number.

1373137921 is a deficient number, since it is larger than the sum of its proper divisors (352191).

1373137921 is an equidigital number, since it uses as much as digits as its factorization.

1373137921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352190.

The product of its digits is 23814, while the sum is 37.

The square root of 1373137921 is about 37055.8756609529. The cubic root of 1373137921 is about 1111.4878516562.

The spelling of 1373137921 in words is "one billion, three hundred seventy-three million, one hundred thirty-seven thousand, nine hundred twenty-one".