197391840 has 48 divisors (see below), whose sum is σ = 621785808. Its totient is φ = 52637696.

The previous prime is 197391827. The next prime is 197391841. The reversal of 197391840 is 48193791.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 197391792 and 197391801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197391841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 205137 + ... + 206096.

It is an arithmetic number, because the mean of its divisors is an integer number (12953871).

Almost surely, 2^197391840 is an apocalyptic number.

197391840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

197391840 is an abundant number, since it is smaller than the sum of its proper divisors (424393968).

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

197391840 is a wasteful number, since it uses less digits than its factorization.

197391840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411251 (or 411243 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 197391840 is about 14049.6206354478. The cubic root of 197391840 is about 582.2503144985.

The spelling of 197391840 in words is "one hundred ninety-seven million, three hundred ninety-one thousand, eight hundred forty".