21151315442 has 8 divisors (see below), whose sum is σ = 33593265756. Its totient is φ = 9953560192.

The previous prime is 21151315429. The next prime is 21151315477. The reversal of 21151315442 is 24451315112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20249574601 + 901740841 = 142301^2 + 30029^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311048723 + ... + 311048790.

Almost surely, 2^21151315442 is an apocalyptic number.

21151315442 is a deficient number, since it is larger than the sum of its proper divisors (12441950314).

21151315442 is a wasteful number, since it uses less digits than its factorization.

21151315442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622097532.

The product of its digits is 4800, while the sum is 29.

The spelling of 21151315442 in words is "twenty-one billion, one hundred fifty-one million, three hundred fifteen thousand, four hundred forty-two".