21124623642 has 64 divisors (see below), whose sum is σ = 44025569280. Its totient is φ = 6749233344.

The previous prime is 21124623629. The next prime is 21124623647. The reversal of 21124623642 is 24632642112.

It is a super-2 number, since 2×21124623642² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21124623647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21845043 + ... + 21846009.

It is an arithmetic number, because the mean of its divisors is an integer number (687899520).

Almost surely, 2^21124623642 is an apocalyptic number.

21124623642 is an abundant number, since it is smaller than the sum of its proper divisors (22900945638).

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

21124623642 is a wasteful number, since it uses less digits than its factorization.

21124623642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1787.

The product of its digits is 27648, while the sum is 33.

The spelling of 21124623642 in words is "twenty-one billion, one hundred twenty-four million, six hundred twenty-three thousand, six hundred forty-two".