642121123326215 has 32 divisors (see below), whose sum is σ = 878633229821760. Its totient is φ = 446287522166784.

The previous prime is 642121123326211. The next prime is 642121123326227. The reversal of 642121123326215 is 512623321121246.

It is a cyclic number.

It is not a de Polignac number, because 642121123326215 - 2² = 642121123326211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642121123326211) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 716375552 + ... + 717271338.

It is an arithmetic number, because the mean of its divisors is an integer number (27457288431930).

Almost surely, 2^{642121123326215} is an apocalyptic number.

642121123326215 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

642121123326215 is a deficient number, since it is larger than the sum of its proper divisors (236512106495545).

642121123326215 is a wasteful number, since it uses less digits than its factorization.

642121123326215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1544531.

The product of its digits is 207360, while the sum is 41.

The spelling of 642121123326215 in words is "six hundred forty-two trillion, one hundred twenty-one billion, one hundred twenty-three million, three hundred twenty-six thousand, two hundred fifteen".