1553978620 has 12 divisors (see below), whose sum is σ = 3263355144. Its totient is φ = 621591440.

The previous prime is 1553978567. The next prime is 1553978641. The reversal of 1553978620 is 268793551.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38849446 + ... + 38849485.

It is an arithmetic number, because the mean of its divisors is an integer number (271946262).

Almost surely, 2^1553978620 is an apocalyptic number.

1553978620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1553978620 is an abundant number, since it is smaller than the sum of its proper divisors (1709376524).

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

1553978620 is a wasteful number, since it uses less digits than its factorization.

1553978620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77698940 (or 77698938 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 46.

The square root of 1553978620 is about 39420.5355113296. The cubic root of 1553978620 is about 1158.2838823439.

The spelling of 1553978620 in words is "one billion, five hundred fifty-three million, nine hundred seventy-eight thousand, six hundred twenty".