21351513442 has 16 divisors (see below), whose sum is σ = 36807082560. Its totient is φ = 9099526608.

The previous prime is 21351513437. The next prime is 21351513493. The reversal of 21351513442 is 24431515312.

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, 4257573 + ... + 4262584.

It is an arithmetic number, because the mean of its divisors is an integer number (2300442660).

Almost surely, 2^21351513442 is an apocalyptic number.

21351513442 is a deficient number, since it is larger than the sum of its proper divisors (15455569118).

21351513442 is a wasteful number, since it uses less digits than its factorization.

21351513442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8520345.

The product of its digits is 14400, while the sum is 31.

The spelling of 21351513442 in words is "twenty-one billion, three hundred fifty-one million, five hundred thirteen thousand, four hundred forty-two".