21155154523006 has 32 divisors (see below), whose sum is σ = 36726705792000. Its totient is φ = 8951323541472.

The previous prime is 21155154522937. The next prime is 21155154523079. The reversal of 21155154523006 is 60032545155112.

It is a super-2 number, since 2×21155154523006² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21155154523006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24650025 + ... + 25493803.

It is an arithmetic number, because the mean of its divisors is an integer number (1147709556000).

Almost surely, 2^{21155154523006} is an apocalyptic number.

21155154523006 is a deficient number, since it is larger than the sum of its proper divisors (15571551268994).

21155154523006 is a wasteful number, since it uses less digits than its factorization.

21155154523006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866536.

The product of its (nonzero) digits is 180000, while the sum is 40.

Adding to 21155154523006 its reverse (60032545155112), we get a palindrome (81187699678118).

The spelling of 21155154523006 in words is "twenty-one trillion, one hundred fifty-five billion, one hundred fifty-four million, five hundred twenty-three thousand, six".