1780390081 has 2 divisors, whose sum is σ = 1780390082. Its totient is φ = 1780390080.

The previous prime is 1780390063. The next prime is 1780390111. The reversal of 1780390081 is 1800930871.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1268499456 + 511890625 = 35616^2 + 22625^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1780390081 is a prime.

It is a super-2 number, since 2×1780390081² = 6339577681046373122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1780390081.

It is not a weakly prime, because it can be changed into another prime (1780394081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 890195040 + 890195041.

It is an arithmetic number, because the mean of its divisors is an integer number (890195041).

Almost surely, 2^1780390081 is an apocalyptic number.

It is an amenable number.

1780390081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1780390081 is an equidigital number, since it uses as much as digits as its factorization.

1780390081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 1780390081 is about 42194.6688694200. The cubic root of 1780390081 is about 1212.0067969081.

The spelling of 1780390081 in words is "one billion, seven hundred eighty million, three hundred ninety thousand, eighty-one".