21145195078 has 16 divisors (see below), whose sum is σ = 36251069184. Its totient is φ = 9061685640.

The previous prime is 21145195033. The next prime is 21145195087. The reversal of 21145195078 is 87059154112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 277513 + ... + 345403.

It is an arithmetic number, because the mean of its divisors is an integer number (2265691824).

Almost surely, 2^21145195078 is an apocalyptic number.

21145195078 is a deficient number, since it is larger than the sum of its proper divisors (15105874106).

21145195078 is a wasteful number, since it uses less digits than its factorization.

21145195078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90147.

The product of its (nonzero) digits is 100800, while the sum is 43.

The spelling of 21145195078 in words is "twenty-one billion, one hundred forty-five million, one hundred ninety-five thousand, seventy-eight".