21213611504651 has 2 divisors, whose sum is σ = 21213611504652. Its totient is φ = 21213611504650.

The previous prime is 21213611504633. The next prime is 21213611504707. The reversal of 21213611504651 is 15640511631212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21213611504651 is a prime.

It is a super-2 number, since 2×21213611504651² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21213611504621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606805752325 + 10606805752326.

It is an arithmetic number, because the mean of its divisors is an integer number (10606805752326).

Almost surely, 2^{21213611504651} is an apocalyptic number.

21213611504651 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213611504651 is an equidigital number, since it uses as much as digits as its factorization.

21213611504651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43200, while the sum is 38.

The spelling of 21213611504651 in words is "twenty-one trillion, two hundred thirteen billion, six hundred eleven million, five hundred four thousand, six hundred fifty-one".