19649856 has 56 divisors (see below), whose sum is σ = 52998624. Its totient is φ = 6423040.

The previous prime is 19649837. The next prime is 19649867. The reversal of 19649856 is 65894691.

It is a super-2 number, since 2×19649856² = 772233681641472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9211 + ... + 11141.

It is an arithmetic number, because the mean of its divisors is an integer number (946404).

Almost surely, 2^19649856 is an apocalyptic number.

19649856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19649856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26499312).

19649856 is an abundant number, since it is smaller than the sum of its proper divisors (33348768).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19649856 is a wasteful number, since it uses less digits than its factorization.

19649856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1999 (or 1989 counting only the distinct ones).

The product of its digits is 466560, while the sum is 48.

The square root of 19649856 is about 4432.8158093925. The cubic root of 19649856 is about 269.8483647872.

The spelling of 19649856 in words is "nineteen million, six hundred forty-nine thousand, eight hundred fifty-six".