21142338378 has 32 divisors (see below), whose sum is σ = 48332522880. Its totient is φ = 6039770880.

The previous prime is 21142338367. The next prime is 21142338397. The reversal of 21142338378 is 87383324112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 280558 + ... + 347846.

It is an arithmetic number, because the mean of its divisors is an integer number (1510391340).

Almost surely, 2^21142338378 is an apocalyptic number.

21142338378 is an abundant number, since it is smaller than the sum of its proper divisors (27190184502).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21142338378 is a wasteful number, since it uses less digits than its factorization.

21142338378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74782.

The product of its digits is 193536, while the sum is 42.

The spelling of 21142338378 in words is "twenty-one billion, one hundred forty-two million, three hundred thirty-eight thousand, three hundred seventy-eight".