21545021202407 has 2 divisors, whose sum is σ = 21545021202408. Its totient is φ = 21545021202406.

The previous prime is 21545021202377. The next prime is 21545021202431. The reversal of 21545021202407 is 70420212054512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21545021202407 - 2¹⁰ = 21545021201383 is a prime.

It is a super-2 number, since 2×21545021202407² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21545021202437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772510601203 + 10772510601204.

It is an arithmetic number, because the mean of its divisors is an integer number (10772510601204).

Almost surely, 2^{21545021202407} is an apocalyptic number.

21545021202407 is a deficient number, since it is larger than the sum of its proper divisors (1).

21545021202407 is an equidigital number, since it uses as much as digits as its factorization.

21545021202407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 44800, while the sum is 35.

Adding to 21545021202407 its reverse (70420212054512), we get a palindrome (91965233256919).

The spelling of 21545021202407 in words is "twenty-one trillion, five hundred forty-five billion, twenty-one million, two hundred two thousand, four hundred seven".