1531620828 has 36 divisors (see below), whose sum is σ = 3873910768. Its totient is φ = 510235200.

The previous prime is 1531620823. The next prime is 1531620841. The reversal of 1531620828 is 8280261351.

It is a happy number.

1531620828 is a `hidden beast` number, since 1 + 5 + 3 + 1 + 620 + 8 + 28 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1531620792 and 1531620801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531620821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53025 + ... + 76647.

Almost surely, 2^1531620828 is an apocalyptic number.

1531620828 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1531620828 is an abundant number, since it is smaller than the sum of its proper divisors (2342289940).

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

1531620828 is a wasteful number, since it uses less digits than its factorization.

1531620828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25434 (or 25429 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 1531620828 is about 39135.9275857875. The cubic root of 1531620828 is about 1152.7021092527.

The spelling of 1531620828 in words is "one billion, five hundred thirty-one million, six hundred twenty thousand, eight hundred twenty-eight".