15405405242221 has 8 divisors (see below), whose sum is σ = 15432756785280. Its totient is φ = 15378054672288.

The previous prime is 15405405242177. The next prime is 15405405242287. The reversal of 15405405242221 is 12224250450451.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15405405242221 is a prime.

It is a super-3 number, since 3×15405405242221³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15405402242221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36311500 + ... + 36733306.

It is an arithmetic number, because the mean of its divisors is an integer number (1929094598160).

Almost surely, 2^{15405405242221} is an apocalyptic number.

It is an amenable number.

15405405242221 is a deficient number, since it is larger than the sum of its proper divisors (27351543059).

15405405242221 is an equidigital number, since it uses as much as digits as its factorization.

15405405242221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486563.

The product of its (nonzero) digits is 128000, while the sum is 37.

Adding to 15405405242221 its reverse (12224250450451), we get a palindrome (27629655692672).

The spelling of 15405405242221 in words is "fifteen trillion, four hundred five billion, four hundred five million, two hundred forty-two thousand, two hundred twenty-one".