26215493021 has 2 divisors, whose sum is σ = 26215493022. Its totient is φ = 26215493020.

The previous prime is 26215493011. The next prime is 26215493107. The reversal of 26215493021 is 12039451262.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23910436900 + 2305056121 = 154630^2 + 48011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26215493021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26215493011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13107746510 + 13107746511.

It is an arithmetic number, because the mean of its divisors is an integer number (13107746511).

Almost surely, 2^26215493021 is an apocalyptic number.

It is an amenable number.

26215493021 is a deficient number, since it is larger than the sum of its proper divisors (1).

26215493021 is an equidigital number, since it uses as much as digits as its factorization.

26215493021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 35.

The spelling of 26215493021 in words is "twenty-six billion, two hundred fifteen million, four hundred ninety-three thousand, twenty-one".