209978148 has 24 divisors (see below), whose sum is σ = 491819328. Its totient is φ = 69725536.

The previous prime is 209978147. The next prime is 209978161. The reversal of 209978148 is 841879902.

It is a super-3 number, since 3×209978148³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 209978097 and 209978106.

It is not an unprimeable number, because it can be changed into a prime (209978143) 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, 30111 + ... + 36422.

It is an arithmetic number, because the mean of its divisors is an integer number (20492472).

Almost surely, 2^209978148 is an apocalyptic number.

It is an amenable number.

209978148 is an abundant number, since it is smaller than the sum of its proper divisors (281841180).

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

209978148 is a wasteful number, since it uses less digits than its factorization.

209978148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66803 (or 66801 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 48.

The square root of 209978148 is about 14490.6227609444. The cubic root of 209978148 is about 594.3715776433.

The spelling of 209978148 in words is "two hundred nine million, nine hundred seventy-eight thousand, one hundred forty-eight".