21235654643061 has 16 divisors (see below), whose sum is σ = 30564060658560. Its totient is φ = 13074625945920.

The previous prime is 21235654643039. The next prime is 21235654643069. The reversal of 21235654643061 is 16034645653212.

It is not a de Polignac number, because 21235654643061 - 2⁷ = 21235654642933 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21235654643061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235654643069) 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, 5306258530 + ... + 5306262531.

It is an arithmetic number, because the mean of its divisors is an integer number (1910253791160).

Almost surely, 2^{21235654643061} is an apocalyptic number.

It is an amenable number.

21235654643061 is a deficient number, since it is larger than the sum of its proper divisors (9328406015499).

21235654643061 is a wasteful number, since it uses less digits than its factorization.

21235654643061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10612521116.

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 21235654643061 in words is "twenty-one trillion, two hundred thirty-five billion, six hundred fifty-four million, six hundred forty-three thousand, sixty-one".