661011051 has 8 divisors (see below), whose sum is σ = 933192144. Its totient is φ = 414752000.

The previous prime is 661011041. The next prime is 661011089. The reversal of 661011051 is 150110166.

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

It is a cyclic number.

It is not a de Polignac number, because 661011051 - 2¹¹ = 661009003 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661011041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6480450 + ... + 6480551.

It is an arithmetic number, because the mean of its divisors is an integer number (116649018).

Almost surely, 2^661011051 is an apocalyptic number.

661011051 is a deficient number, since it is larger than the sum of its proper divisors (272181093).

661011051 is a wasteful number, since it uses less digits than its factorization.

661011051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12961021.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 661011051 is about 25710.1351805081. The cubic root of 661011051 is about 871.1031283609.

The spelling of 661011051 in words is "six hundred sixty-one million, eleven thousand, fifty-one".