21234477278 has 32 divisors (see below), whose sum is σ = 37590251520. Its totient is φ = 8803637280.

The previous prime is 21234477259. The next prime is 21234477281. The reversal of 21234477278 is 87277443212.

It is a congruent number.

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, 1406900 + ... + 1421912.

It is an arithmetic number, because the mean of its divisors is an integer number (1174695360).

Almost surely, 2^21234477278 is an apocalyptic number.

21234477278 is a deficient number, since it is larger than the sum of its proper divisors (16355774242).

21234477278 is a wasteful number, since it uses less digits than its factorization.

21234477278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18312.

The product of its digits is 1053696, while the sum is 47.

The spelling of 21234477278 in words is "twenty-one billion, two hundred thirty-four million, four hundred seventy-seven thousand, two hundred seventy-eight".