1638969854 has 32 divisors (see below), whose sum is σ = 2554066944. Its totient is φ = 788296320.

The previous prime is 1638969851. The next prime is 1638969863. The reversal of 1638969854 is 4589698361.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 1638969793 and 1638969802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638969851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1855697 + ... + 1856579.

It is an arithmetic number, because the mean of its divisors is an integer number (79814592).

Almost surely, 2^1638969854 is an apocalyptic number.

1638969854 is a deficient number, since it is larger than the sum of its proper divisors (915097090).

1638969854 is a wasteful number, since it uses less digits than its factorization.

1638969854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1232.

The product of its digits is 11197440, while the sum is 59.

The square root of 1638969854 is about 40484.1926435492. The cubic root of 1638969854 is about 1179.0267408109.

The spelling of 1638969854 in words is "one billion, six hundred thirty-eight million, nine hundred sixty-nine thousand, eight hundred fifty-four".