21142120387 has 2 divisors, whose sum is σ = 21142120388. Its totient is φ = 21142120386.

The previous prime is 21142120361. The next prime is 21142120411. The reversal of 21142120387 is 78302124112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21142120387 is a prime.

It is not a weakly prime, because it can be changed into another prime (21142120327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571060193 + 10571060194.

It is an arithmetic number, because the mean of its divisors is an integer number (10571060194).

Almost surely, 2^21142120387 is an apocalyptic number.

21142120387 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142120387 is an equidigital number, since it uses as much as digits as its factorization.

21142120387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 31.

Adding to 21142120387 its reverse (78302124112), we get a palindrome (99444244499).

The spelling of 21142120387 in words is "twenty-one billion, one hundred forty-two million, one hundred twenty thousand, three hundred eighty-seven".