21552315642 has 192 divisors, whose sum is σ = 57104611200. Its totient is φ = 5784629760.

The previous prime is 21552315601. The next prime is 21552315643. The reversal of 21552315642 is 24651325512.

21552315642 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 2 + 3 + 1 + 5 + 642 = 666.

It is a super-3 number, since 3×21552315642³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21552315597 and 21552315606.

It is not an unprimeable number, because it can be changed into a prime (21552315643) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13360828 + ... + 13362440.

It is an arithmetic number, because the mean of its divisors is an integer number (297419850).

Almost surely, 2^21552315642 is an apocalyptic number.

21552315642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21552315642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28552305600).

21552315642 is an abundant number, since it is smaller than the sum of its proper divisors (35552295558).

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

21552315642 is a wasteful number, since it uses less digits than its factorization.

21552315642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1853 (or 1850 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The spelling of 21552315642 in words is "twenty-one billion, five hundred fifty-two million, three hundred fifteen thousand, six hundred forty-two".