2051561611 has 16 divisors (see below), whose sum is σ = 2267388288. Its totient is φ = 1840753600.

The previous prime is 2051561599. The next prime is 2051561627. The reversal of 2051561611 is 1161651502.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2051561611 - 2²³ = 2043173003 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2051561611.

It is not an unprimeable number, because it can be changed into a prime (2051561011) 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, 327636 + ... + 333838.

It is an arithmetic number, because the mean of its divisors is an integer number (141711768).

Almost surely, 2^2051561611 is an apocalyptic number.

2051561611 is a deficient number, since it is larger than the sum of its proper divisors (215826677).

2051561611 is a wasteful number, since it uses less digits than its factorization.

2051561611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6602.

The product of its (nonzero) digits is 1800, while the sum is 28.

The square root of 2051561611 is about 45294.1675163591. The cubic root of 2051561611 is about 1270.6565747541.

The spelling of 2051561611 in words is "two billion, fifty-one million, five hundred sixty-one thousand, six hundred eleven".