21535343042 has 4 divisors (see below), whose sum is σ = 32303014566. Its totient is φ = 10767671520.

The previous prime is 21535343023. The next prime is 21535343057. The reversal of 21535343042 is 24034353512.

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

It can be written as a sum of positive squares in only one way, i.e., 16452936361 + 5082406681 = 128269^2 + 71291^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5383835759 + ... + 5383835762.

Almost surely, 2^21535343042 is an apocalyptic number.

21535343042 is a deficient number, since it is larger than the sum of its proper divisors (10767671524).

21535343042 is a wasteful number, since it uses less digits than its factorization.

21535343042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10767671523.

The product of its (nonzero) digits is 43200, while the sum is 32.

Adding to 21535343042 its reverse (24034353512), we get a palindrome (45569696554).

The spelling of 21535343042 in words is "twenty-one billion, five hundred thirty-five million, three hundred forty-three thousand, forty-two".