19661964 has 48 divisors (see below), whose sum is σ = 54716928. Its totient is φ = 5372928.

The previous prime is 19661951. The next prime is 19661989. The reversal of 19661964 is 46916691.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3157 + ... + 7020.

It is an arithmetic number, because the mean of its divisors is an integer number (1139936).

Almost surely, 2^19661964 is an apocalyptic number.

19661964 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

19661964 is an abundant number, since it is smaller than the sum of its proper divisors (35054964).

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

19661964 is a wasteful number, since it uses less digits than its factorization.

19661964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10214 (or 10212 counting only the distinct ones).

The product of its digits is 69984, while the sum is 42.

The square root of 19661964 is about 4434.1813224089. The cubic root of 19661964 is about 269.9037791566.

The spelling of 19661964 in words is "nineteen million, six hundred sixty-one thousand, nine hundred sixty-four".