21357533978707 has 2 divisors, whose sum is σ = 21357533978708. Its totient is φ = 21357533978706.

The previous prime is 21357533978663. The next prime is 21357533978731. The reversal of 21357533978707 is 70787933575312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21357533978707 - 2⁷ = 21357533978579 is a prime.

It is a super-2 number, since 2×21357533978707² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21357533976707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678766989353 + 10678766989354.

It is an arithmetic number, because the mean of its divisors is an integer number (10678766989354).

Almost surely, 2^{21357533978707} is an apocalyptic number.

21357533978707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357533978707 is an equidigital number, since it uses as much as digits as its factorization.

21357533978707 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233377200, while the sum is 67.

The spelling of 21357533978707 in words is "twenty-one trillion, three hundred fifty-seven billion, five hundred thirty-three million, nine hundred seventy-eight thousand, seven hundred seven".