2661405653 has 16 divisors (see below), whose sum is σ = 2796498432. Its totient is φ = 2530320000.

The previous prime is 2661405631. The next prime is 2661405701. The reversal of 2661405653 is 3565041662.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2661405653 - 2⁶ = 2661405589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661405623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 324068 + ... + 332178.

It is an arithmetic number, because the mean of its divisors is an integer number (174781152).

Almost surely, 2^2661405653 is an apocalyptic number.

It is an amenable number.

2661405653 is a deficient number, since it is larger than the sum of its proper divisors (135092779).

2661405653 is a wasteful number, since it uses less digits than its factorization.

2661405653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8356.

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 2661405653 is about 51588.8132544256. The cubic root of 2661405653 is about 1385.8100025381.

The spelling of 2661405653 in words is "two billion, six hundred sixty-one million, four hundred five thousand, six hundred fifty-three".