21234154178 has 16 divisors (see below), whose sum is σ = 33904332000. Its totient is φ = 9945267552.

The previous prime is 21234154171. The next prime is 21234154213. The reversal of 21234154178 is 87145143212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is not an unprimeable number, because it can be changed into a prime (21234154171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3135908 + ... + 3142671.

It is an arithmetic number, because the mean of its divisors is an integer number (2119020750).

Almost surely, 2^21234154178 is an apocalyptic number.

21234154178 is a deficient number, since it is larger than the sum of its proper divisors (12670177822).

21234154178 is a wasteful number, since it uses less digits than its factorization.

21234154178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6278689.

The product of its digits is 53760, while the sum is 38.

The spelling of 21234154178 in words is "twenty-one billion, two hundred thirty-four million, one hundred fifty-four thousand, one hundred seventy-eight".