21030212507 has 2 divisors, whose sum is σ = 21030212508. Its totient is φ = 21030212506.

The previous prime is 21030212393. The next prime is 21030212561. The reversal of 21030212507 is 70521203012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21030212507 - 2¹⁸ = 21029950363 is a prime.

It is not a weakly prime, because it can be changed into another prime (21030212207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515106253 + 10515106254.

It is an arithmetic number, because the mean of its divisors is an integer number (10515106254).

Almost surely, 2^21030212507 is an apocalyptic number.

21030212507 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030212507 is an equidigital number, since it uses as much as digits as its factorization.

21030212507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 23.

Adding to 21030212507 its reverse (70521203012), we get a palindrome (91551415519).

The spelling of 21030212507 in words is "twenty-one billion, thirty million, two hundred twelve thousand, five hundred seven".