21125071507 has 2 divisors, whose sum is σ = 21125071508. Its totient is φ = 21125071506.

The previous prime is 21125071453. The next prime is 21125071537. The reversal of 21125071507 is 70517052112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21125071507 - 2³¹ = 18977587859 is a prime.

It is not a weakly prime, because it can be changed into another prime (21125071537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562535753 + 10562535754.

It is an arithmetic number, because the mean of its divisors is an integer number (10562535754).

Almost surely, 2^21125071507 is an apocalyptic number.

21125071507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21125071507 is an equidigital number, since it uses as much as digits as its factorization.

21125071507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4900, while the sum is 31.

The spelling of 21125071507 in words is "twenty-one billion, one hundred twenty-five million, seventy-one thousand, five hundred seven".