21046458397 has 2 divisors, whose sum is σ = 21046458398. Its totient is φ = 21046458396.

The previous prime is 21046458283. The next prime is 21046458443. The reversal of 21046458397 is 79385464012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20408693881 + 637764516 = 142859^2 + 25254^2 .

It is a cyclic number.

It is not a de Polignac number, because 21046458397 - 2²⁷ = 20912240669 is a prime.

It is a super-2 number, since 2×21046458397² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21046458397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21046458997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10523229198 + 10523229199.

It is an arithmetic number, because the mean of its divisors is an integer number (10523229199).

It is a 1-persistent number, because it is pandigital, but 2⋅21046458397 = 42092916794 is not.

Almost surely, 2^21046458397 is an apocalyptic number.

It is an amenable number.

21046458397 is a deficient number, since it is larger than the sum of its proper divisors (1).

21046458397 is an equidigital number, since it uses as much as digits as its factorization.

21046458397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The spelling of 21046458397 in words is "twenty-one billion, forty-six million, four hundred fifty-eight thousand, three hundred ninety-seven".