15421420215 has 24 divisors (see below), whose sum is σ = 26934521328. Its totient is φ = 8161969920.

The previous prime is 15421420211. The next prime is 15421420247. The reversal of 15421420215 is 51202412451.

It is a happy number.

15421420215 is a `hidden beast` number, since 1 + 5 + 4 + 21 + 420 + 215 = 666.

It is not a de Polignac number, because 15421420215 - 2² = 15421420211 is a prime.

It is a super-2 number, since 2×15421420215² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15421420211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1302114 + ... + 1313903.

It is an arithmetic number, because the mean of its divisors is an integer number (1122271722).

Almost surely, 2^15421420215 is an apocalyptic number.

15421420215 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

15421420215 is a deficient number, since it is larger than the sum of its proper divisors (11513101113).

15421420215 is a wasteful number, since it uses less digits than its factorization.

15421420215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2616159 (or 2616156 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

Adding to 15421420215 its reverse (51202412451), we get a palindrome (66623832666).

The spelling of 15421420215 in words is "fifteen billion, four hundred twenty-one million, four hundred twenty thousand, two hundred fifteen".