20401133555 has 16 divisors (see below), whose sum is σ = 26899084800. Its totient is φ = 14730440160.

The previous prime is 20401133507. The next prime is 20401133579. The reversal of 20401133555 is 55533110402.

It is a de Polignac number, because none of the positive numbers 2^k-20401133555 is a prime.

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, 1326635 + ... + 1341924.

It is an arithmetic number, because the mean of its divisors is an integer number (1681192800).

Almost surely, 2^20401133555 is an apocalyptic number.

20401133555 is a deficient number, since it is larger than the sum of its proper divisors (6497951245).

20401133555 is a wasteful number, since it uses less digits than its factorization.

20401133555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668714.

The product of its (nonzero) digits is 9000, while the sum is 29.

Adding to 20401133555 its reverse (55533110402), we get a palindrome (75934243957).

The spelling of 20401133555 in words is "twenty billion, four hundred one million, one hundred thirty-three thousand, five hundred fifty-five".