197661219840 has 1408 divisors, whose sum is σ = 855723294720. Its totient is φ = 42295689216.

The previous prime is 197661219751. The next prime is 197661219841. The reversal of 197661219840 is 48912166791.

197661219840 is a `hidden beast` number, since 1 + 9 + 7 + 6 + 612 + 19 + 8 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197661219841) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1847301067 + ... + 1847301173.

Almost surely, 2^197661219840 is an apocalyptic number.

197661219840 is a gapful number since it is divisible by the number (10) 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 197661219840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (427861647360).

197661219840 is an abundant number, since it is smaller than the sum of its proper divisors (658062074880).

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

197661219840 is a wasteful number, since it uses less digits than its factorization.

197661219840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 197661219840 in words is "one hundred ninety-seven billion, six hundred sixty-one million, two hundred nineteen thousand, eight hundred forty".