155479991 has 4 divisors (see below), whose sum is σ = 160841400. Its totient is φ = 150118584.

The previous prime is 155479981. The next prime is 155479993. The reversal of 155479991 is 199974551.

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 155479991 - 2¹⁸ = 155217847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155479993) 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, 2680661 + ... + 2680718.

It is an arithmetic number, because the mean of its divisors is an integer number (40210350).

Almost surely, 2^155479991 is an apocalyptic number.

155479991 is a deficient number, since it is larger than the sum of its proper divisors (5361409).

155479991 is an equidigital number, since it uses as much as digits as its factorization.

155479991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5361408.

The product of its digits is 510300, while the sum is 50.

The square root of 155479991 is about 12469.1615997227. The cubic root of 155479991 is about 537.7224502710.

The spelling of 155479991 in words is "one hundred fifty-five million, four hundred seventy-nine thousand, nine hundred ninety-one".