661012519 has 2 divisors, whose sum is σ = 661012520. Its totient is φ = 661012518.

The previous prime is 661012501. The next prime is 661012567. The reversal of 661012519 is 915210166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661012519 - 2¹⁵ = 660979751 is a prime.

It is a super-2 number, since 2×661012519² = 873875100549450722, which contains 22 as substring.

It is equal to p_34336093 and since 661012519 and 34336093 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661013519) by changing a digit.

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 as a sum of consecutive naturals, namely, 330506259 + 330506260.

It is an arithmetic number, because the mean of its divisors is an integer number (330506260).

Almost surely, 2^661012519 is an apocalyptic number.

661012519 is a deficient number, since it is larger than the sum of its proper divisors (1).

661012519 is an equidigital number, since it uses as much as digits as its factorization.

661012519 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 661012519 is about 25710.1637295448. The cubic root of 661012519 is about 871.1037732207.

The spelling of 661012519 in words is "six hundred sixty-one million, twelve thousand, five hundred nineteen".