266721946 has 4 divisors (see below), whose sum is σ = 400082922. Its totient is φ = 133360972.

The previous prime is 266721929. The next prime is 266721989. The reversal of 266721946 is 649127662.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 258084225 + 8637721 = 16065^2 + 2939^2 .

It is a super-2 number, since 2×266721946² = 142281192956053832, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66680485 + ... + 66680488.

Almost surely, 2^266721946 is an apocalyptic number.

266721946 is a deficient number, since it is larger than the sum of its proper divisors (133360976).

266721946 is a wasteful number, since it uses less digits than its factorization.

266721946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133360975.

The product of its digits is 217728, while the sum is 43.

The square root of 266721946 is about 16331.6241078467. The cubic root of 266721946 is about 643.7040630054.

The spelling of 266721946 in words is "two hundred sixty-six million, seven hundred twenty-one thousand, nine hundred forty-six".