1551403640 has 32 divisors (see below), whose sum is σ = 3491948880. Its totient is φ = 620332032.

The previous prime is 1551403639. The next prime is 1551403657. The reversal of 1551403640 is 463041551.

It is a happy number.

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, 139319 + ... + 150041.

Almost surely, 2^1551403640 is an apocalyptic number.

1551403640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1551403640 is an abundant number, since it is smaller than the sum of its proper divisors (1940545240).

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

1551403640 is a wasteful number, since it uses less digits than its factorization.

1551403640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14351 (or 14347 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 1551403640 is about 39387.8615819646. The cubic root of 1551403640 is about 1157.6437605513.

The spelling of 1551403640 in words is "one billion, five hundred fifty-one million, four hundred three thousand, six hundred forty".