1535974943221 has 2 divisors, whose sum is σ = 1535974943222. Its totient is φ = 1535974943220.

The previous prime is 1535974943207. The next prime is 1535974943273. The reversal of 1535974943221 is 1223494795351.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1526250222225 + 9724720996 = 1235415^2 + 98614^2 .

It is a cyclic number.

It is not a de Polignac number, because 1535974943221 - 2⁷ = 1535974943093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1535975943221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 767987471610 + 767987471611.

It is an arithmetic number, because the mean of its divisors is an integer number (767987471611).

Almost surely, 2^{1535974943221} is an apocalyptic number.

It is an amenable number.

1535974943221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1535974943221 is an equidigital number, since it uses as much as digits as its factorization.

1535974943221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8164800, while the sum is 55.

The spelling of 1535974943221 in words is "one trillion, five hundred thirty-five billion, nine hundred seventy-four million, nine hundred forty-three thousand, two hundred twenty-one".