1661415525 has 144 divisors (see below), whose sum is σ = 3928998528. Its totient is φ = 649728000.

The previous prime is 1661415523. The next prime is 1661415617. The reversal of 1661415525 is 5255141661.

1661415525 is a `hidden beast` number, since 1 + 6 + 61 + 41 + 552 + 5 = 666.

It is not a de Polignac number, because 1661415525 - 2¹ = 1661415523 is a prime.

It is a super-2 number, since 2×1661415525² = 5520603093422051250, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1661415525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661415523) 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 in 143 ways as a sum of consecutive naturals, for example, 291705 + ... + 297345.

It is an arithmetic number, because the mean of its divisors is an integer number (27284712).

Almost surely, 2^1661415525 is an apocalyptic number.

1661415525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1661415525 is an abundant number, since it is smaller than the sum of its proper divisors (2267583003).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661415525 is a wasteful number, since it uses less digits than its factorization.

1661415525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5692 (or 5684 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 1661415525 is about 40760.4652206032. The cubic root of 1661415525 is about 1184.3846081003.

The spelling of 1661415525 in words is "one billion, six hundred sixty-one million, four hundred fifteen thousand, five hundred twenty-five".