661343515 has 8 divisors (see below), whose sum is σ = 906985440. Its totient is φ = 453492672.

The previous prime is 661343479. The next prime is 661343531. The reversal of 661343515 is 515343166.

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 661343515 - 2⁷ = 661343387 is a prime.

It is an unprimeable number.

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, 9447730 + ... + 9447799.

It is an arithmetic number, because the mean of its divisors is an integer number (113373180).

Almost surely, 2^661343515 is an apocalyptic number.

661343515 is a deficient number, since it is larger than the sum of its proper divisors (245641925).

661343515 is a wasteful number, since it uses less digits than its factorization.

661343515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18895541.

The product of its digits is 32400, while the sum is 34.

The square root of 661343515 is about 25716.5999891121. The cubic root of 661343515 is about 871.2491480526.

The spelling of 661343515 in words is "six hundred sixty-one million, three hundred forty-three thousand, five hundred fifteen".