15553402020 has 144 divisors (see below), whose sum is σ = 50855134512. Its totient is φ = 3824962560.

The previous prime is 15553401991. The next prime is 15553402031. The reversal of 15553402020 is 2020435551.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 388957284 + 15164444736 = 19722^2 + 123144^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3229134 + ... + 3233946.

Almost surely, 2^15553402020 is an apocalyptic number.

15553402020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15553402020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25427567256).

15553402020 is an abundant number, since it is smaller than the sum of its proper divisors (35301732492).

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

15553402020 is a wasteful number, since it uses less digits than its factorization.

15553402020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6222 (or 6217 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

Adding to 15553402020 its reverse (2020435551), we get a palindrome (17573837571).

The spelling of 15553402020 in words is "fifteen billion, five hundred fifty-three million, four hundred two thousand, twenty".