21154435142 has 4 divisors (see below), whose sum is σ = 31731652716. Its totient is φ = 10577217570.

The previous prime is 21154435139. The next prime is 21154435151. The reversal of 21154435142 is 24153445112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21154435099 and 21154435108.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5288608784 + ... + 5288608787.

It is an arithmetic number, because the mean of its divisors is an integer number (7932913179).

Almost surely, 2^21154435142 is an apocalyptic number.

21154435142 is a deficient number, since it is larger than the sum of its proper divisors (10577217574).

21154435142 is a wasteful number, since it uses less digits than its factorization.

21154435142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10577217573.

The product of its digits is 19200, while the sum is 32.

The spelling of 21154435142 in words is "twenty-one billion, one hundred fifty-four million, four hundred thirty-five thousand, one hundred forty-two".