6401387915 has 32 divisors (see below), whose sum is σ = 8379504000. Its totient is φ = 4694252160.

The previous prime is 6401387897. The next prime is 6401387929. The reversal of 6401387915 is 5197831046.

It is a de Polignac number, because none of the positive numbers 2^k-6401387915 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1634810 + ... + 1638720.

It is an arithmetic number, because the mean of its divisors is an integer number (261859500).

Almost surely, 2^6401387915 is an apocalyptic number.

6401387915 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

6401387915 is a deficient number, since it is larger than the sum of its proper divisors (1978116085).

6401387915 is a wasteful number, since it uses less digits than its factorization.

6401387915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4104 (or 4078 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 6401387915 is about 80008.6739985109. The cubic root of 6401387915 is about 1856.7697348022.

The spelling of 6401387915 in words is "six billion, four hundred one million, three hundred eighty-seven thousand, nine hundred fifteen".