21152354540 has 24 divisors (see below), whose sum is σ = 44453676960. Its totient is φ = 8454516608.

The previous prime is 21152354479. The next prime is 21152354611. The reversal of 21152354540 is 4545325112.

It is a super-2 number, since 2×21152354540² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21152354497 and 21152354506.

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, 374537 + ... + 427296.

It is an arithmetic number, because the mean of its divisors is an integer number (1852236540).

Almost surely, 2^21152354540 is an apocalyptic number.

21152354540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21152354540 is an abundant number, since it is smaller than the sum of its proper divisors (23301322420).

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

21152354540 is a wasteful number, since it uses less digits than its factorization.

21152354540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 803161 (or 803159 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 21152354540 its reverse (4545325112), we get a palindrome (25697679652).

The spelling of 21152354540 in words is "twenty-one billion, one hundred fifty-two million, three hundred fifty-four thousand, five hundred forty".