21445251151531 has 2 divisors, whose sum is σ = 21445251151532. Its totient is φ = 21445251151530.

The previous prime is 21445251151469. The next prime is 21445251151579. The reversal of 21445251151531 is 13515115254412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21445251151531 - 2³⁷ = 21307812198059 is a prime.

It is a super-2 number, since 2×21445251151531² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21445251851531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722625575765 + 10722625575766.

It is an arithmetic number, because the mean of its divisors is an integer number (10722625575766).

Almost surely, 2^{21445251151531} is an apocalyptic number.

21445251151531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21445251151531 is an equidigital number, since it uses as much as digits as its factorization.

21445251151531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120000, while the sum is 40.

The spelling of 21445251151531 in words is "twenty-one trillion, four hundred forty-five billion, two hundred fifty-one million, one hundred fifty-one thousand, five hundred thirty-one".