15515515001655 has 32 divisors (see below), whose sum is σ = 27971632696320. Its totient is φ = 8158392859680.

The previous prime is 15515515001647. The next prime is 15515515001711. The reversal of 15515515001655 is 55610051551551.

It is not a de Polignac number, because 15515515001655 - 2³ = 15515515001647 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 15515515001655.

It is a congruent number.

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, 809354787 + ... + 809373956.

It is an arithmetic number, because the mean of its divisors is an integer number (874113521760).

Almost surely, 2^{15515515001655} is an apocalyptic number.

15515515001655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

15515515001655 is a deficient number, since it is larger than the sum of its proper divisors (12456117694665).

15515515001655 is a wasteful number, since it uses less digits than its factorization.

15515515001655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618728828 (or 1618728822 counting only the distinct ones).

The product of its (nonzero) digits is 468750, while the sum is 45.

The spelling of 15515515001655 in words is "fifteen trillion, five hundred fifteen billion, five hundred fifteen million, one thousand, six hundred fifty-five".