661511026 has 16 divisors (see below), whose sum is σ = 1082870208. Its totient is φ = 300576400.

The previous prime is 661510957. The next prime is 661511029. The reversal of 661511026 is 620115166.

It is a junction number, because it is equal to n+sod(n) for n = 661510985 and 661511003.

It is not an unprimeable number, because it can be changed into a prime (661511029) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 104076 + ... + 110248.

It is an arithmetic number, because the mean of its divisors is an integer number (67679388).

Almost surely, 2^661511026 is an apocalyptic number.

661511026 is a deficient number, since it is larger than the sum of its proper divisors (421359182).

661511026 is a wasteful number, since it uses less digits than its factorization.

661511026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11057.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 661511026 is about 25719.8566481231. The cubic root of 661511026 is about 871.3227011015.

The spelling of 661511026 in words is "six hundred sixty-one million, five hundred eleven thousand, twenty-six".