660917949 has 16 divisors (see below), whose sum is σ = 933268992. Its totient is φ = 415161648.

The previous prime is 660917911. The next prime is 660917951. The reversal of 660917949 is 949719066.

It is not a de Polignac number, because 660917949 - 2⁷ = 660917821 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660917549) 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, 66859 + ... + 76104.

It is an arithmetic number, because the mean of its divisors is an integer number (58329312).

Almost surely, 2^660917949 is an apocalyptic number.

660917949 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

It is an amenable number.

660917949 is a deficient number, since it is larger than the sum of its proper divisors (272351043).

660917949 is a wasteful number, since it uses less digits than its factorization.

660917949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143056.

The product of its (nonzero) digits is 734832, while the sum is 51.

The square root of 660917949 is about 25708.3245078321. The cubic root of 660917949 is about 871.0622287666.

The spelling of 660917949 in words is "six hundred sixty million, nine hundred seventeen thousand, nine hundred forty-nine".