21256043542534 has 8 divisors (see below), whose sum is σ = 33759598567608. Its totient is φ = 10002844020000.

The previous prime is 21256043542511. The next prime is 21256043542553. The reversal of 21256043542534 is 43524534065212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312588875592 + ... + 312588875659.

It is an arithmetic number, because the mean of its divisors is an integer number (4219949820951).

Almost surely, 2^{21256043542534} is an apocalyptic number.

21256043542534 is a deficient number, since it is larger than the sum of its proper divisors (12503555025074).

21256043542534 is a wasteful number, since it uses less digits than its factorization.

21256043542534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625177751270.

The product of its (nonzero) digits is 3456000, while the sum is 46.

The spelling of 21256043542534 in words is "twenty-one trillion, two hundred fifty-six billion, forty-three million, five hundred forty-two thousand, five hundred thirty-four".