15745397881 has 4 divisors (see below), whose sum is σ = 15766198372. Its totient is φ = 15724597392.

The previous prime is 15745397851. The next prime is 15745397933. The reversal of 15745397881 is 18879354751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18879354751 = 4513 ⋅4183327.

It can be written as a sum of positive squares in 2 ways, for example, as 7153776400 + 8591621481 = 84580^2 + 92691^2 .

It is a cyclic number.

It is not a de Polignac number, because 15745397881 - 2¹¹ = 15745395833 is a prime.

It is a super-2 number, since 2×15745397881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15745397821) 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, 10399110 + ... + 10400623.

It is an arithmetic number, because the mean of its divisors is an integer number (3941549593).

Almost surely, 2^15745397881 is an apocalyptic number.

It is an amenable number.

15745397881 is a deficient number, since it is larger than the sum of its proper divisors (20800491).

15745397881 is an equidigital number, since it uses as much as digits as its factorization.

15745397881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20800490.

The product of its digits is 8467200, while the sum is 58.

The spelling of 15745397881 in words is "fifteen billion, seven hundred forty-five million, three hundred ninety-seven thousand, eight hundred eighty-one".