155020691 has 4 divisors (see below), whose sum is σ = 177166512. Its totient is φ = 132874872.

The previous prime is 155020627. The next prime is 155020693. The reversal of 155020691 is 196020551.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 155020691 - 2⁶ = 155020627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155020693) 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, 11072900 + ... + 11072913.

It is an arithmetic number, because the mean of its divisors is an integer number (44291628).

Almost surely, 2^155020691 is an apocalyptic number.

155020691 is a deficient number, since it is larger than the sum of its proper divisors (22145821).

155020691 is an equidigital number, since it uses as much as digits as its factorization.

155020691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22145820.

The product of its (nonzero) digits is 2700, while the sum is 29.

The square root of 155020691 is about 12450.7305408157. The cubic root of 155020691 is about 537.1924366980.

The spelling of 155020691 in words is "one hundred fifty-five million, twenty thousand, six hundred ninety-one".