1927381721 has 2 divisors, whose sum is σ = 1927381722. Its totient is φ = 1927381720.

The previous prime is 1927381699. The next prime is 1927381739. The reversal of 1927381721 is 1271837291.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1860714496 + 66667225 = 43136^2 + 8165^2 .

It is an emirp because it is prime and its reverse (1271837291) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1927381721 - 2⁶ = 1927381657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1927381741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 963690860 + 963690861.

It is an arithmetic number, because the mean of its divisors is an integer number (963690861).

Almost surely, 2^1927381721 is an apocalyptic number.

It is an amenable number.

1927381721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1927381721 is an equidigital number, since it uses as much as digits as its factorization.

1927381721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 41.

The square root of 1927381721 is about 43901.9557764799. The cubic root of 1927381721 is about 1244.4837934603.

The spelling of 1927381721 in words is "one billion, nine hundred twenty-seven million, three hundred eighty-one thousand, seven hundred twenty-one".