15212421540 has 96 divisors (see below), whose sum is σ = 48959568000. Its totient is φ = 3916757376.

The previous prime is 15212421529. The next prime is 15212421563. The reversal of 15212421540 is 4512421251.

It is a happy number.

It is a super-2 number, since 2×15212421540² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 470050 + ... + 501369.

It is an arithmetic number, because the mean of its divisors is an integer number (509995500).

Almost surely, 2^15212421540 is an apocalyptic number.

15212421540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15212421540 is an abundant number, since it is smaller than the sum of its proper divisors (33747146460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15212421540 is a wasteful number, since it uses less digits than its factorization.

15212421540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 971466 (or 971458 counting only the distinct ones).

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

Adding to 15212421540 its reverse (4512421251), we get a palindrome (19724842791).

The spelling of 15212421540 in words is "fifteen billion, two hundred twelve million, four hundred twenty-one thousand, five hundred forty".