1641525661 has 8 divisors (see below), whose sum is σ = 1764028800. Its totient is φ = 1521905088.

The previous prime is 1641525649. The next prime is 1641525679. The reversal of 1641525661 is 1665251461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1641525661 - 2⁷ = 1641525533 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1641525661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1641525601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 719461 + ... + 721738.

It is an arithmetic number, because the mean of its divisors is an integer number (220503600).

Almost surely, 2^1641525661 is an apocalyptic number.

It is an amenable number.

1641525661 is a deficient number, since it is larger than the sum of its proper divisors (122503139).

1641525661 is a wasteful number, since it uses less digits than its factorization.

1641525661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1441283.

The product of its digits is 43200, while the sum is 37.

The square root of 1641525661 is about 40515.7458403520. The cubic root of 1641525661 is about 1179.6392800024.

The spelling of 1641525661 in words is "one billion, six hundred forty-one million, five hundred twenty-five thousand, six hundred sixty-one".