1538407840 has 48 divisors (see below), whose sum is σ = 3684304008. Its totient is φ = 606928896.

The previous prime is 1538407823. The next prime is 1538407859. The reversal of 1538407840 is 487048351.

It can be written as a sum of positive squares in 4 ways, for example, as 1381757584 + 156650256 = 37172^2 + 12516^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1538407793 and 1538407802.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54177 + ... + 77536.

Almost surely, 2^1538407840 is an apocalyptic number.

1538407840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1538407840 is an abundant number, since it is smaller than the sum of its proper divisors (2145896168).

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

1538407840 is a wasteful number, since it uses less digits than its factorization.

1538407840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131801 (or 131793 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 40.

The square root of 1538407840 is about 39222.5424979055. The cubic root of 1538407840 is about 1154.4022418665.

The spelling of 1538407840 in words is "one billion, five hundred thirty-eight million, four hundred seven thousand, eight hundred forty".