21361729497 has 16 divisors (see below), whose sum is σ = 28537662912. Its totient is φ = 14213505600.

The previous prime is 21361729483. The next prime is 21361729511. The reversal of 21361729497 is 79492716312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21361729483) and next prime (21361729511).

It is not a de Polignac number, because 21361729497 - 2¹⁰ = 21361728473 is a prime.

It is a super-3 number, since 3×21361729497³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21361729097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3897523 + ... + 3902999.

It is an arithmetic number, because the mean of its divisors is an integer number (1783603932).

Almost surely, 2^21361729497 is an apocalyptic number.

It is an amenable number.

21361729497 is a deficient number, since it is larger than the sum of its proper divisors (7175933415).

21361729497 is a wasteful number, since it uses less digits than its factorization.

21361729497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7768.

The product of its digits is 1143072, while the sum is 51.

The spelling of 21361729497 in words is "twenty-one billion, three hundred sixty-one million, seven hundred twenty-nine thousand, four hundred ninety-seven".