1961039081 has 2 divisors, whose sum is σ = 1961039082. Its totient is φ = 1961039080.

The previous prime is 1961039071. The next prime is 1961039089. The reversal of 1961039081 is 1809301691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1833552400 + 127486681 = 42820^2 + 11291^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961039081 - 2²² = 1956844777 is a prime.

It is a super-2 number, since 2×1961039081² = 7691348554418649122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1961039089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980519540 + 980519541.

It is an arithmetic number, because the mean of its divisors is an integer number (980519541).

Almost surely, 2^1961039081 is an apocalyptic number.

It is an amenable number.

1961039081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961039081 is an equidigital number, since it uses as much as digits as its factorization.

1961039081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 38.

The square root of 1961039081 is about 44283.6209111224. The cubic root of 1961039081 is about 1251.6860620134.

The spelling of 1961039081 in words is "one billion, nine hundred sixty-one million, thirty-nine thousand, eighty-one".