155923937978 has 4 divisors (see below), whose sum is σ = 233885906970. Its totient is φ = 77961968988.

The previous prime is 155923937977. The next prime is 155923937989. The reversal of 155923937978 is 879739329551.

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: 879739329551 = 107 ⋅8221862893.

It can be written as a sum of positive squares in only one way, i.e., 155825194009 + 98743969 = 394747^2 + 9937^2 .

It is not an unprimeable number, because it can be changed into a prime (155923937977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38980984493 + ... + 38980984496.

Almost surely, 2^155923937978 is an apocalyptic number.

155923937978 is a deficient number, since it is larger than the sum of its proper divisors (77961968992).

155923937978 is an equidigital number, since it uses as much as digits as its factorization.

155923937978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77961968991.

The product of its digits is 128595600, while the sum is 68.

It can be divided in two parts, 155923 and 937978, that added together give a palindrome (1093901).

The spelling of 155923937978 in words is "one hundred fifty-five billion, nine hundred twenty-three million, nine hundred thirty-seven thousand, nine hundred seventy-eight".