243991972 has 18 divisors (see below), whose sum is σ = 496698342. Its totient is φ = 104567904.

The previous prime is 243991967. The next prime is 243991999. The reversal of 243991972 is 279199342.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 150405696 + 93586276 = 12264^2 + 9674^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 622233 + ... + 622624.

Almost surely, 2^243991972 is an apocalyptic number.

It is an amenable number.

243991972 is an abundant number, since it is smaller than the sum of its proper divisors (252706370).

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

243991972 is a wasteful number, since it uses less digits than its factorization.

243991972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244875 (or 1244866 counting only the distinct ones).

The product of its digits is 244944, while the sum is 46.

The square root of 243991972 is about 15620.2423796816. The cubic root of 243991972 is about 624.8731236856.

The spelling of 243991972 in words is "two hundred forty-three million, nine hundred ninety-one thousand, nine hundred seventy-two".