21525545542 has 4 divisors (see below), whose sum is σ = 32288318316. Its totient is φ = 10762772770.

The previous prime is 21525545527. The next prime is 21525545549. The reversal of 21525545542 is 24554552512.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21525545542² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21525545495 and 21525545504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525545549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5381386384 + ... + 5381386387.

It is an arithmetic number, because the mean of its divisors is an integer number (8072079579).

Almost surely, 2^21525545542 is an apocalyptic number.

21525545542 is a deficient number, since it is larger than the sum of its proper divisors (10762772774).

21525545542 is a wasteful number, since it uses less digits than its factorization.

21525545542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10762772773.

The product of its digits is 400000, while the sum is 40.

The spelling of 21525545542 in words is "twenty-one billion, five hundred twenty-five million, five hundred forty-five thousand, five hundred forty-two".