21210255121042 has 8 divisors (see below), whose sum is σ = 34262719810956. Its totient is φ = 9789348517392.

The previous prime is 21210255120991. The next prime is 21210255121063. The reversal of 21210255121042 is 24012155201212.

It can be written as a sum of positive squares in 2 ways, for example, as 16181318805201 + 5028936315841 = 4022601^2 + 2242529^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21210255121042.

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, 407889521533 + ... + 407889521584.

Almost surely, 2^{21210255121042} is an apocalyptic number.

21210255121042 is a deficient number, since it is larger than the sum of its proper divisors (13052464689914).

21210255121042 is a wasteful number, since it uses less digits than its factorization.

21210255121042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815779043132.

The product of its (nonzero) digits is 3200, while the sum is 28.

The spelling of 21210255121042 in words is "twenty-one trillion, two hundred ten billion, two hundred fifty-five million, one hundred twenty-one thousand, forty-two".