21551000742 has 24 divisors (see below), whose sum is σ = 49440531816. Its totient is φ = 6761098176.

The previous prime is 21551000729. The next prime is 21551000767. The reversal of 21551000742 is 24700015512.

21551000742 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35213748 + ... + 35214359.

It is an arithmetic number, because the mean of its divisors is an integer number (2060022159).

Almost surely, 2^21551000742 is an apocalyptic number.

21551000742 is an abundant number, since it is smaller than the sum of its proper divisors (27889531074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21551000742 is a wasteful number, since it uses less digits than its factorization.

21551000742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70428132 (or 70428129 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The spelling of 21551000742 in words is "twenty-one billion, five hundred fifty-one million, seven hundred forty-two", and thus it is an aban number.