21150036051661 has 16 divisors (see below), whose sum is σ = 23710670343360. Its totient is φ = 18699557224320.

The previous prime is 21150036051659. The next prime is 21150036051709. The reversal of 21150036051661 is 16615063005112.

It is a cyclic number.

It is not a de Polignac number, because 21150036051661 - 2¹ = 21150036051659 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21150036051661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150036051061) 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, 95844006 + ... + 96064423.

It is an arithmetic number, because the mean of its divisors is an integer number (1481916896460).

Almost surely, 2^{21150036051661} is an apocalyptic number.

It is an amenable number.

21150036051661 is a deficient number, since it is larger than the sum of its proper divisors (2560634291699).

21150036051661 is a wasteful number, since it uses less digits than its factorization.

21150036051661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191908716.

The product of its (nonzero) digits is 32400, while the sum is 37.

Adding to 21150036051661 its reverse (16615063005112), we get a palindrome (37765099056773).

The spelling of 21150036051661 in words is "twenty-one trillion, one hundred fifty billion, thirty-six million, fifty-one thousand, six hundred sixty-one".