661522015 has 32 divisors (see below), whose sum is σ = 991673856. Its totient is φ = 411557760.

The previous prime is 661521997. The next prime is 661522049. The reversal of 661522015 is 510225166.

It is not a de Polignac number, because 661522015 - 2¹⁷ = 661390943 is a prime.

It is a super-2 number, since 2×661522015² = 875222752659320450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 234604 + ... + 237406.

It is an arithmetic number, because the mean of its divisors is an integer number (30989808).

Almost surely, 2^661522015 is an apocalyptic number.

661522015 is a deficient number, since it is larger than the sum of its proper divisors (330151841).

661522015 is a wasteful number, since it uses less digits than its factorization.

661522015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3439.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 661522015 is about 25720.0702759538. The cubic root of 661522015 is about 871.3275258697.

The spelling of 661522015 in words is "six hundred sixty-one million, five hundred twenty-two thousand, fifteen".