661151011 has 2 divisors, whose sum is σ = 661151012. Its totient is φ = 661151010.

The previous prime is 661151009. The next prime is 661151017. The reversal of 661151011 is 110151166.

661151011 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661151011 - 2¹ = 661151009 is a prime.

Together with 661151009, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (661151017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330575505 + 330575506.

It is an arithmetic number, because the mean of its divisors is an integer number (330575506).

Almost surely, 2^661151011 is an apocalyptic number.

661151011 is a deficient number, since it is larger than the sum of its proper divisors (1).

661151011 is an equidigital number, since it uses as much as digits as its factorization.

661151011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 661151011 is about 25712.8569202257. The cubic root of 661151011 is about 871.1646053915.

The spelling of 661151011 in words is "six hundred sixty-one million, one hundred fifty-one thousand, eleven".