155555720 has 16 divisors (see below), whose sum is σ = 350000460. Its totient is φ = 62222272.

The previous prime is 155555677. The next prime is 155555783. The reversal of 155555720 is 27555551.

It can be written as a sum of positive squares in 2 ways, for example, as 153115876 + 2439844 = 12374^2 + 1562^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1944407 + ... + 1944486.

Almost surely, 2^155555720 is an apocalyptic number.

155555720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

155555720 is an abundant number, since it is smaller than the sum of its proper divisors (194444740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

155555720 is a wasteful number, since it uses less digits than its factorization.

155555720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3888904 (or 3888900 counting only the distinct ones).

The product of its (nonzero) digits is 43750, while the sum is 35.

The square root of 155555720 is about 12472.1978816887. The cubic root of 155555720 is about 537.8097381886.

It can be divided in two parts, 1555 and 55720, that added together give a palindrome (57275).

The spelling of 155555720 in words is "one hundred fifty-five million, five hundred fifty-five thousand, seven hundred twenty".