1551640540 has 24 divisors (see below), whose sum is σ = 3259251072. Its totient is φ = 620502720.

The previous prime is 1551640511. The next prime is 1551640579. The reversal of 1551640540 is 450461551.

It is a congruent number.

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, 109122 + ... + 122518.

It is an arithmetic number, because the mean of its divisors is an integer number (135802128).

Almost surely, 2^1551640540 is an apocalyptic number.

1551640540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1551640540 is an abundant number, since it is smaller than the sum of its proper divisors (1707610532).

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

1551640540 is a wasteful number, since it uses less digits than its factorization.

1551640540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19197 (or 19195 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 31.

The square root of 1551640540 is about 39390.8687388334. The cubic root of 1551640540 is about 1157.7026817849.

The spelling of 1551640540 in words is "one billion, five hundred fifty-one million, six hundred forty thousand, five hundred forty".