21145650061 has 16 divisors (see below), whose sum is σ = 21648168000. Its totient is φ = 20648678400.

The previous prime is 21145650013. The next prime is 21145650077. The reversal of 21145650061 is 16005654112.

It is a cyclic number.

It is not a de Polignac number, because 21145650061 - 2⁷ = 21145649933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21145650161) 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, 5777250 + ... + 5780908.

It is an arithmetic number, because the mean of its divisors is an integer number (1353010500).

Almost surely, 2^21145650061 is an apocalyptic number.

It is an amenable number.

21145650061 is a deficient number, since it is larger than the sum of its proper divisors (502517939).

21145650061 is a wasteful number, since it uses less digits than its factorization.

21145650061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4380.

The product of its (nonzero) digits is 7200, while the sum is 31.

The spelling of 21145650061 in words is "twenty-one billion, one hundred forty-five million, six hundred fifty thousand, sixty-one".