21012054394 has 8 divisors (see below), whose sum is σ = 32369921748. Its totient is φ = 10222080480.

The previous prime is 21012054391. The next prime is 21012054397. The reversal of 21012054394 is 49345021012.

It is an interprime number because it is at equal distance from previous prime (21012054391) and next prime (21012054397).

It can be written as a sum of positive squares in 2 ways, for example, as 20890944369 + 121110025 = 144537^2 + 11005^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21012054391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141973267 + ... + 141973414.

Almost surely, 2^21012054394 is an apocalyptic number.

21012054394 is a deficient number, since it is larger than the sum of its proper divisors (11357867354).

21012054394 is a wasteful number, since it uses less digits than its factorization.

21012054394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283946720.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 21012054394 in words is "twenty-one billion, twelve million, fifty-four thousand, three hundred ninety-four".