21403432542 has 16 divisors (see below), whose sum is σ = 44282964240. Its totient is φ = 6888460992.

The previous prime is 21403432541. The next prime is 21403432553. The reversal of 21403432542 is 24523430412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21403432541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61503943 + ... + 61504290.

It is an arithmetic number, because the mean of its divisors is an integer number (2767685265).

Almost surely, 2^21403432542 is an apocalyptic number.

21403432542 is an abundant number, since it is smaller than the sum of its proper divisors (22879531698).

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

21403432542 is a wasteful number, since it uses less digits than its factorization.

21403432542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123008267.

The product of its (nonzero) digits is 23040, while the sum is 30.

Adding to 21403432542 its reverse (24523430412), we get a palindrome (45926862954).

The spelling of 21403432542 in words is "twenty-one billion, four hundred three million, four hundred thirty-two thousand, five hundred forty-two".