1661412515 has 32 divisors (see below), whose sum is σ = 2299691520. Its totient is φ = 1128720384.

The previous prime is 1661412461. The next prime is 1661412527. The reversal of 1661412515 is 5152141661.

It is a cyclic number.

It is not a de Polignac number, because 1661412515 - 2¹⁰ = 1661411491 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2830052 + ... + 2830638.

It is an arithmetic number, because the mean of its divisors is an integer number (71865360).

Almost surely, 2^1661412515 is an apocalyptic number.

1661412515 is a deficient number, since it is larger than the sum of its proper divisors (638279005).

1661412515 is a wasteful number, since it uses less digits than its factorization.

1661412515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1211.

The product of its digits is 7200, while the sum is 32.

The square root of 1661412515 is about 40760.4282975535. The cubic root of 1661412515 is about 1184.3838928468.

The spelling of 1661412515 in words is "one billion, six hundred sixty-one million, four hundred twelve thousand, five hundred fifteen".