20151226620555 has 32 divisors (see below), whose sum is σ = 33990154149888. Its totient is φ = 10179343017600.

The previous prime is 20151226620533. The next prime is 20151226620557. The reversal of 20151226620555 is 55502662215102.

It is a happy number.

It is not a de Polignac number, because 20151226620555 - 2⁶ = 20151226620491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20151226620557) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 460999116 + ... + 461042825.

It is an arithmetic number, because the mean of its divisors is an integer number (1062192317184).

Almost surely, 2^{20151226620555} is an apocalyptic number.

20151226620555 is a deficient number, since it is larger than the sum of its proper divisors (13838927529333).

20151226620555 is a wasteful number, since it uses less digits than its factorization.

20151226620555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 922042027.

The product of its (nonzero) digits is 360000, while the sum is 42.

Adding to 20151226620555 its reverse (55502662215102), we get a palindrome (75653888835657).

The spelling of 20151226620555 in words is "twenty trillion, one hundred fifty-one billion, two hundred twenty-six million, six hundred twenty thousand, five hundred fifty-five".