15402120040 has 32 divisors (see below), whose sum is σ = 34670063880. Its totient is φ = 6158129152.

The previous prime is 15402119987. The next prime is 15402120047. The reversal of 15402120040 is 4002120451.

It can be written as a sum of positive squares in 4 ways, for example, as 6516041284 + 8886078756 = 80722^2 + 94266^2 .

It is not an unprimeable number, because it can be changed into a prime (15402120047) 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, 8064 + ... + 175696.

Almost surely, 2^15402120040 is an apocalyptic number.

15402120040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15402120040 is an abundant number, since it is smaller than the sum of its proper divisors (19267943840).

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

15402120040 is a wasteful number, since it uses less digits than its factorization.

15402120040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169941 (or 169937 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

Adding to 15402120040 its reverse (4002120451), we get a palindrome (19404240491).

The spelling of 15402120040 in words is "fifteen billion, four hundred two million, one hundred twenty thousand, forty".