1661513425 has 96 divisors (see below), whose sum is σ = 2596083840. Its totient is φ = 1036800000.

The previous prime is 1661513407. The next prime is 1661513429. The reversal of 1661513425 is 5243151661.

It is not a de Polignac number, because 1661513425 - 2¹⁷ = 1661382353 is a prime.

It is a super-2 number, since 2×1661513425² = 5521253722910461250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1661513429) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4143225 + ... + 4143625.

It is an arithmetic number, because the mean of its divisors is an integer number (27042540).

Almost surely, 2^1661513425 is an apocalyptic number.

It is an amenable number.

1661513425 is a deficient number, since it is larger than the sum of its proper divisors (934570415).

1661513425 is a wasteful number, since it uses less digits than its factorization.

1661513425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515 (or 510 counting only the distinct ones).

The product of its digits is 21600, while the sum is 34.

The square root of 1661513425 is about 40761.6661214921. Note that the first 3 decimals coincide. The cubic root of 1661513425 is about 1184.4078711901.

The spelling of 1661513425 in words is "one billion, six hundred sixty-one million, five hundred thirteen thousand, four hundred twenty-five".