2661366621 has 64 divisors (see below), whose sum is σ = 3866252544. Its totient is φ = 1625702400.

The previous prime is 2661366619. The next prime is 2661366649. The reversal of 2661366621 is 1266631662.

It is not a de Polignac number, because 2661366621 - 2¹ = 2661366619 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2661366621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661366601) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23551861 + ... + 23551973.

It is an arithmetic number, because the mean of its divisors is an integer number (60410196).

Almost surely, 2^2661366621 is an apocalyptic number.

It is an amenable number.

2661366621 is a deficient number, since it is larger than the sum of its proper divisors (1204885923).

2661366621 is a wasteful number, since it uses less digits than its factorization.

2661366621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334.

The product of its digits is 93312, while the sum is 39.

The square root of 2661366621 is about 51588.4349539701. The cubic root of 2661366621 is about 1385.8032277722.

The spelling of 2661366621 in words is "two billion, six hundred sixty-one million, three hundred sixty-six thousand, six hundred twenty-one".