21355356040620 has 96 divisors (see below), whose sum is σ = 69791121082368. Its totient is φ = 4777368398592.

The previous prime is 21355356040457. The next prime is 21355356040621. The reversal of 21355356040620 is 2604065355312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (21355356040621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 540896067 + ... + 540935546.

It is an arithmetic number, because the mean of its divisors is an integer number (726990844608).

Almost surely, 2^{21355356040620} is an apocalyptic number.

21355356040620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21355356040620 is an abundant number, since it is smaller than the sum of its proper divisors (48435765041748).

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

21355356040620 is a wasteful number, since it uses less digits than its factorization.

21355356040620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081831679 (or 1081831677 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 42.

The spelling of 21355356040620 in words is "twenty-one trillion, three hundred fifty-five billion, three hundred fifty-six million, forty thousand, six hundred twenty".