16215165977 has 4 divisors (see below), whose sum is σ = 16272871476. Its totient is φ = 16157460480.

The previous prime is 16215165961. The next prime is 16215165997. The reversal of 16215165977 is 77956151261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77956151261 = 170447 ⋅457363.

It can be written as a sum of positive squares in 2 ways, for example, as 9851753536 + 6363412441 = 99256^2 + 79771^2 .

It is a cyclic number.

It is not a de Polignac number, because 16215165977 - 2⁴ = 16215165961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16215165907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28852328 + ... + 28852889.

It is an arithmetic number, because the mean of its divisors is an integer number (4068217869).

Almost surely, 2^16215165977 is an apocalyptic number.

It is an amenable number.

16215165977 is a deficient number, since it is larger than the sum of its proper divisors (57705499).

16215165977 is an equidigital number, since it uses as much as digits as its factorization.

16215165977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57705498.

The product of its digits is 793800, while the sum is 50.

The spelling of 16215165977 in words is "sixteen billion, two hundred fifteen million, one hundred sixty-five thousand, nine hundred seventy-seven".