19641040 has 20 divisors (see below), whose sum is σ = 45665604. Its totient is φ = 7856384.

The previous prime is 19641019. The next prime is 19641047. The reversal of 19641040 is 4014691.

It can be written as a sum of positive squares in 2 ways, for example, as 7862416 + 11778624 = 2804^2 + 3432^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 19640996 and 19641014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19641047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122677 + ... + 122836.

Almost surely, 2^19641040 is an apocalyptic number.

19641040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19641040 is an abundant number, since it is smaller than the sum of its proper divisors (26024564).

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

19641040 is a wasteful number, since it uses less digits than its factorization.

19641040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245526 (or 245520 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 19641040 is about 4431.8212960362. The cubic root of 19641040 is about 269.8080025058.

The spelling of 19641040 in words is "nineteen million, six hundred forty-one thousand, forty".