1372871821 has 2 divisors, whose sum is σ = 1372871822. Its totient is φ = 1372871820.

The previous prime is 1372871807. The next prime is 1372871827. The reversal of 1372871821 is 1281782731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1224300100 + 148571721 = 34990^2 + 12189^2 .

It is a cyclic number.

It is not a de Polignac number, because 1372871821 - 2⁵ = 1372871789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1372871827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 686435910 + 686435911.

It is an arithmetic number, because the mean of its divisors is an integer number (686435911).

Almost surely, 2^1372871821 is an apocalyptic number.

It is an amenable number.

1372871821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1372871821 is an equidigital number, since it uses as much as digits as its factorization.

1372871821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37632, while the sum is 40.

The square root of 1372871821 is about 37052.2849632786. The cubic root of 1372871821 is about 1111.4160487148.

The spelling of 1372871821 in words is "one billion, three hundred seventy-two million, eight hundred seventy-one thousand, eight hundred twenty-one".