197978949 has 24 divisors (see below), whose sum is σ = 328553472. Its totient is φ = 112531680.

The previous prime is 197978947. The next prime is 197978983. The reversal of 197978949 is 949879791.

It is not a de Polignac number, because 197978949 - 2¹ = 197978947 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197978941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3807 + ... + 20259.

It is an arithmetic number, because the mean of its divisors is an integer number (13689728).

Almost surely, 2^197978949 is an apocalyptic number.

It is an amenable number.

197978949 is a deficient number, since it is larger than the sum of its proper divisors (130574523).

197978949 is a wasteful number, since it uses less digits than its factorization.

197978949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16657 (or 16654 counting only the distinct ones).

The product of its digits is 10287648, while the sum is 63.

The square root of 197978949 is about 14070.4992448740. The cubic root of 197978949 is about 582.8270118250.

The spelling of 197978949 in words is "one hundred ninety-seven million, nine hundred seventy-eight thousand, nine hundred forty-nine".