21356205642070 has 64 divisors (see below), whose sum is σ = 45739169320320. Its totient is φ = 7098848114688.

The previous prime is 21356205642043. The next prime is 21356205642097. The reversal of 21356205642070 is 7024650265312.

It is an interprime number because it is at equal distance from previous prime (21356205642043) and next prime (21356205642097).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 210023985 + ... + 210125644.

It is an arithmetic number, because the mean of its divisors is an integer number (714674520630).

Almost surely, 2^{21356205642070} is an apocalyptic number.

21356205642070 is an abundant number, since it is smaller than the sum of its proper divisors (24382963678250).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21356205642070 is a wasteful number, since it uses less digits than its factorization.

21356205642070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420149689.

The product of its (nonzero) digits is 604800, while the sum is 43.

The spelling of 21356205642070 in words is "twenty-one trillion, three hundred fifty-six billion, two hundred five million, six hundred forty-two thousand, seventy".