1661025323641 has 8 divisors (see below), whose sum is σ = 1672043667840. Its totient is φ = 1650019742688.

The previous prime is 1661025323621. The next prime is 1661025323663. The reversal of 1661025323641 is 1463235201661.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661025323641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1661025323594 and 1661025323603.

It is not an unprimeable number, because it can be changed into a prime (1661025323621) 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, 2929596 + ... + 3450301.

It is an arithmetic number, because the mean of its divisors is an integer number (209005458480).

Almost surely, 2^{1661025323641} is an apocalyptic number.

It is an amenable number.

1661025323641 is a deficient number, since it is larger than the sum of its proper divisors (11018344199).

1661025323641 is a wasteful number, since it uses less digits than its factorization.

1661025323641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6381623.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 1661025323641 in words is "one trillion, six hundred sixty-one billion, twenty-five million, three hundred twenty-three thousand, six hundred forty-one".