1919908961 has 2 divisors, whose sum is σ = 1919908962. Its totient is φ = 1919908960.

The previous prime is 1919908951. The next prime is 1919908981. The reversal of 1919908961 is 1698099191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1283860561 + 636048400 = 35831^2 + 25220^2 .

It is an emirp because it is prime and its reverse (1698099191) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1968066161 and 1616608691.

It is a cyclic number.

It is not a de Polignac number, because 1919908961 - 2⁶ = 1919908897 is a prime.

It is not a weakly prime, because it can be changed into another prime (1919908931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959954480 + 959954481.

It is an arithmetic number, because the mean of its divisors is an integer number (959954481).

Almost surely, 2^1919908961 is an apocalyptic number.

It is an amenable number.

1919908961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919908961 is an equidigital number, since it uses as much as digits as its factorization.

1919908961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 314928, while the sum is 53.

The square root of 1919908961 is about 43816.7657523921. The cubic root of 1919908961 is about 1242.8733576724.

The spelling of 1919908961 in words is "one billion, nine hundred nineteen million, nine hundred eight thousand, nine hundred sixty-one".