266401615 has 4 divisors (see below), whose sum is σ = 319681944. Its totient is φ = 213121288.

The previous prime is 266401609. The next prime is 266401621. The reversal of 266401615 is 516104662.

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

It is an interprime number because it is at equal distance from previous prime (266401609) and next prime (266401621).

It is a cyclic number.

It is not a de Polignac number, because 266401615 - 2³ = 266401607 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26640157 + ... + 26640166.

It is an arithmetic number, because the mean of its divisors is an integer number (79920486).

Almost surely, 2^266401615 is an apocalyptic number.

266401615 is a deficient number, since it is larger than the sum of its proper divisors (53280329).

266401615 is an equidigital number, since it uses as much as digits as its factorization.

266401615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53280328.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 266401615 is about 16321.8140842248. The cubic root of 266401615 is about 643.4462652352.

The spelling of 266401615 in words is "two hundred sixty-six million, four hundred one thousand, six hundred fifteen".