661144011 has 16 divisors (see below), whose sum is σ = 964154880. Its totient is φ = 399655520.

The previous prime is 661143979. The next prime is 661144019. The reversal of 661144011 is 110441166.

It is not a de Polignac number, because 661144011 - 2⁵ = 661143979 is a prime.

It is a super-2 number, since 2×661144011² = 874222806562336242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661144019) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12915 + ... + 38588.

It is an arithmetic number, because the mean of its divisors is an integer number (60259680).

Almost surely, 2^661144011 is an apocalyptic number.

661144011 is a deficient number, since it is larger than the sum of its proper divisors (303010869).

661144011 is a wasteful number, since it uses less digits than its factorization.

661144011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51906.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 661144011 is about 25712.7208011910. The cubic root of 661144011 is about 871.1615308676.

Adding to 661144011 its reverse (110441166), we get a palindrome (771585177).

It can be divided in two parts, 66114 and 4011, that added together give a triangular number (70125 = T₃₇₄).

The spelling of 661144011 in words is "six hundred sixty-one million, one hundred forty-four thousand, eleven".