21252038578 has 8 divisors (see below), whose sum is σ = 32014874268. Its totient is φ = 10580413824.

The previous prime is 21252038543. The next prime is 21252038603. The reversal of 21252038578 is 87583025212.

It can be written as a sum of positive squares in 2 ways, for example, as 21249767529 + 2271049 = 145773^2 + 1507^2 .

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, 22802151 + ... + 22803082.

Almost surely, 2^21252038578 is an apocalyptic number.

21252038578 is a deficient number, since it is larger than the sum of its proper divisors (10762835690).

21252038578 is a wasteful number, since it uses less digits than its factorization.

21252038578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45605468.

The product of its (nonzero) digits is 268800, while the sum is 43.

The spelling of 21252038578 in words is "twenty-one billion, two hundred fifty-two million, thirty-eight thousand, five hundred seventy-eight".