21655404412106 has 8 divisors (see below), whose sum is σ = 32486309794884. Its totient is φ = 10826634480480.

The previous prime is 21655404412007. The next prime is 21655404412153. The reversal of 21655404412106 is 60121440455612.

It can be written as a sum of positive squares in 2 ways, for example, as 21574250646481 + 81153765625 = 4644809^2 + 284875^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21655404412106² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533837435 + ... + 533877998.

Almost surely, 2^{21655404412106} is an apocalyptic number.

21655404412106 is a deficient number, since it is larger than the sum of its proper divisors (10830905382778).

21655404412106 is a wasteful number, since it uses less digits than its factorization.

21655404412106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067725576.

The product of its (nonzero) digits is 230400, while the sum is 41.

Adding to 21655404412106 its reverse (60121440455612), we get a palindrome (81776844867718).

The spelling of 21655404412106 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred four million, four hundred twelve thousand, one hundred six".