155520001 has 16 divisors (see below), whose sum is σ = 193177600. Its totient is φ = 121912128.

The previous prime is 155519999. The next prime is 155520007. The reversal of 155520001 is 100025551.

It is not a de Polignac number, because 155520001 - 2¹ = 155519999 is a prime.

It is a super-2 number, since 2×155520001² = 48372941422080002, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (155520007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2080 + ... + 17758.

It is an arithmetic number, because the mean of its divisors is an integer number (12073600).

Almost surely, 2^155520001 is an apocalyptic number.

It is an amenable number.

155520001 is a deficient number, since it is larger than the sum of its proper divisors (37657599).

155520001 is a wasteful number, since it uses less digits than its factorization.

155520001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15808.

The product of its (nonzero) digits is 250, while the sum is 19.

The square root of 155520001 is about 12470.7658545897. The cubic root of 155520001 is about 537.7685707395.

Adding to 155520001 its reverse (100025551), we get a palindrome (255545552).

The spelling of 155520001 in words is "one hundred fifty-five million, five hundred twenty thousand, one".