21154374278 has 16 divisors (see below), whose sum is σ = 32981344560. Its totient is φ = 10164050400.

The previous prime is 21154374271. The next prime is 21154374287. The reversal of 21154374278 is 87247345112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154374271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 852053 + ... + 876528.

It is an arithmetic number, because the mean of its divisors is an integer number (2061334035).

Almost surely, 2^21154374278 is an apocalyptic number.

21154374278 is a deficient number, since it is larger than the sum of its proper divisors (11826970282).

21154374278 is a wasteful number, since it uses less digits than its factorization.

21154374278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1728823.

The product of its digits is 376320, while the sum is 44.

The spelling of 21154374278 in words is "twenty-one billion, one hundred fifty-four million, three hundred seventy-four thousand, two hundred seventy-eight".