1264720161 has 8 divisors (see below), whose sum is σ = 1775045920. Its totient is φ = 798770592.

The previous prime is 1264720139. The next prime is 1264720181. The reversal of 1264720161 is 1610274621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1264720161 - 2⁵ = 1264720129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1264720111) 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, 11093980 + ... + 11094093.

It is an arithmetic number, because the mean of its divisors is an integer number (221880740).

Almost surely, 2^1264720161 is an apocalyptic number.

It is an amenable number.

1264720161 is a deficient number, since it is larger than the sum of its proper divisors (510325759).

1264720161 is a wasteful number, since it uses less digits than its factorization.

1264720161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22188095.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 1264720161 is about 35562.9042824120. The cubic root of 1264720161 is about 1081.4293377740.

Adding to 1264720161 its reverse (1610274621), we get a palindrome (2874994782).

The spelling of 1264720161 in words is "one billion, two hundred sixty-four million, seven hundred twenty thousand, one hundred sixty-one".