155661445 has 8 divisors (see below), whose sum is σ = 188893080. Its totient is φ = 123129600.

The previous prime is 155661439. The next prime is 155661449. The reversal of 155661445 is 544166551.

It can be written as a sum of positive squares in 4 ways, for example, as 4322241 + 151339204 = 2079^2 + 12302^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 155661445 - 2⁹ = 155660933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155661449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 174456 + ... + 175345.

It is an arithmetic number, because the mean of its divisors is an integer number (23611635).

Almost surely, 2^155661445 is an apocalyptic number.

It is an amenable number.

155661445 is a deficient number, since it is larger than the sum of its proper divisors (33231635).

155661445 is an equidigital number, since it uses as much as digits as its factorization.

155661445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349895.

The product of its digits is 72000, while the sum is 37.

The square root of 155661445 is about 12476.4355887409. The cubic root of 155661445 is about 537.9315531833.

It can be divided in two parts, 1556 and 61445, that added together give a square (63001 = 251²).

The spelling of 155661445 in words is "one hundred fifty-five million, six hundred sixty-one thousand, four hundred forty-five".