1919662081 has 2 divisors, whose sum is σ = 1919662082. Its totient is φ = 1919662080.

The previous prime is 1919662061. The next prime is 1919662109. The reversal of 1919662081 is 1802669191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1410753600 + 508908481 = 37560^2 + 22559^2 .

It is an emirp because it is prime and its reverse (1802669191) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1919662081 is a prime.

It is a super-2 number, since 2×1919662081² = 7370205010458501122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1919662021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959831040 + 959831041.

It is an arithmetic number, because the mean of its divisors is an integer number (959831041).

Almost surely, 2^1919662081 is an apocalyptic number.

It is an amenable number.

1919662081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919662081 is an equidigital number, since it uses as much as digits as its factorization.

1919662081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 1919662081 is about 43813.9484753429. The cubic root of 1919662081 is about 1242.8200819297.

The spelling of 1919662081 in words is "one billion, nine hundred nineteen million, six hundred sixty-two thousand, eighty-one".