1649778951 has 16 divisors (see below), whose sum is σ = 2255228640. Its totient is φ = 1072135680.

The previous prime is 1649778943. The next prime is 1649778971. The reversal of 1649778951 is 1598779461.

It is not a de Polignac number, because 1649778951 - 2³ = 1649778943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1649778891 and 1649778900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1649778931) 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 15 ways as a sum of consecutive naturals, for example, 163995 + ... + 173763.

It is an arithmetic number, because the mean of its divisors is an integer number (140951790).

Almost surely, 2^1649778951 is an apocalyptic number.

1649778951 is a deficient number, since it is larger than the sum of its proper divisors (605449689).

1649778951 is a wasteful number, since it uses less digits than its factorization.

1649778951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11186.

The product of its digits is 3810240, while the sum is 57.

The square root of 1649778951 is about 40617.4710069448. The cubic root of 1649778951 is about 1181.6129792154.

The spelling of 1649778951 in words is "one billion, six hundred forty-nine million, seven hundred seventy-eight thousand, nine hundred fifty-one".