155638776947 has 4 divisors (see below), whose sum is σ = 159845230416. Its totient is φ = 151432323480.

The previous prime is 155638776919. The next prime is 155638776949. The reversal of 155638776947 is 749677836551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 749677836551 = 7 ⋅107096833793.

It is a cyclic number.

It is not a de Polignac number, because 155638776947 - 2¹² = 155638772851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155638776949) 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, 2103226679 + ... + 2103226752.

It is an arithmetic number, because the mean of its divisors is an integer number (39961307604).

Almost surely, 2^155638776947 is an apocalyptic number.

155638776947 is a deficient number, since it is larger than the sum of its proper divisors (4206453469).

155638776947 is an equidigital number, since it uses as much as digits as its factorization.

155638776947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4206453468.

The product of its digits is 266716800, while the sum is 68.

The spelling of 155638776947 in words is "one hundred fifty-five billion, six hundred thirty-eight million, seven hundred seventy-six thousand, nine hundred forty-seven".