195666387840 has 768 divisors, whose sum is σ = 891968163840. Its totient is φ = 38264832000.

The previous prime is 195666387799. The next prime is 195666387881. The reversal of 195666387840 is 48783666591.

It is an interprime number because it is at equal distance from previous prime (195666387799) and next prime (195666387881).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7526865 + ... + 7552815.

It is an arithmetic number, because the mean of its divisors is an integer number (1161416880).

Almost surely, 2^195666387840 is an apocalyptic number.

195666387840 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 195666387840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (445984081920).

195666387840 is an abundant number, since it is smaller than the sum of its proper divisors (696301776000).

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

195666387840 is a wasteful number, since it uses less digits than its factorization.

195666387840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26011 (or 25996 counting only the distinct ones).

The product of its (nonzero) digits is 52254720, while the sum is 63.

The spelling of 195666387840 in words is "one hundred ninety-five billion, six hundred sixty-six million, three hundred eighty-seven thousand, eight hundred forty".