1779990957 has 20 divisors (see below), whose sum is σ = 2660140956. Its totient is φ = 1186151040.

The previous prime is 1779990937. The next prime is 1779990991. The reversal of 1779990957 is 7590999771.

It can be written as a sum of positive squares in 2 ways, for example, as 1503965961 + 276024996 = 38781^2 + 16614^2 .

It is not a de Polignac number, because 1779990957 - 2⁸ = 1779990701 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1779990894 and 1779990903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1779990937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 335707 + ... + 340967.

Almost surely, 2^1779990957 is an apocalyptic number.

It is an amenable number.

1779990957 is a deficient number, since it is larger than the sum of its proper divisors (880149999).

1779990957 is an equidigital number, since it uses as much as digits as its factorization.

1779990957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9450 (or 9441 counting only the distinct ones).

The product of its (nonzero) digits is 11252115, while the sum is 63.

The square root of 1779990957 is about 42189.9390494938. The cubic root of 1779990957 is about 1211.9162217848.

The spelling of 1779990957 in words is "one billion, seven hundred seventy-nine million, nine hundred ninety thousand, nine hundred fifty-seven".