1372920781 has 2 divisors, whose sum is σ = 1372920782. Its totient is φ = 1372920780.

The previous prime is 1372920763. The next prime is 1372920803. The reversal of 1372920781 is 1870292731.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1306171881 + 66748900 = 36141^2 + 8170^2 .

It is a cyclic number.

It is not a de Polignac number, because 1372920781 - 2¹¹ = 1372918733 is a prime.

It is a super-2 number, since 2×1372920781² = 3769822941803299922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1372920481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 686460390 + 686460391.

It is an arithmetic number, because the mean of its divisors is an integer number (686460391).

Almost surely, 2^1372920781 is an apocalyptic number.

It is an amenable number.

1372920781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1372920781 is an equidigital number, since it uses as much as digits as its factorization.

1372920781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 1372920781 is about 37052.9456453870. The cubic root of 1372920781 is about 1111.4292605049.

The spelling of 1372920781 in words is "one billion, three hundred seventy-two million, nine hundred twenty thousand, seven hundred eighty-one".