21551237284742 has 16 divisors (see below), whose sum is σ = 35265747482064. Its totient is φ = 9795992928000.

The previous prime is 21551237284729. The next prime is 21551237284763. The reversal of 21551237284742 is 24748273215512.

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, 10515242 + ... + 12396482.

It is an arithmetic number, because the mean of its divisors is an integer number (2204109217629).

Almost surely, 2^{21551237284742} is an apocalyptic number.

21551237284742 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21551237284742 is a deficient number, since it is larger than the sum of its proper divisors (13714510197322).

21551237284742 is a wasteful number, since it uses less digits than its factorization.

21551237284742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2401975.

The product of its digits is 7526400, while the sum is 53.

The spelling of 21551237284742 in words is "twenty-one trillion, five hundred fifty-one billion, two hundred thirty-seven million, two hundred eighty-four thousand, seven hundred forty-two".