124721551 has 4 divisors (see below), whose sum is σ = 124991392. Its totient is φ = 124451712.

The previous prime is 124721521. The next prime is 124721579. The reversal of 124721551 is 155127421.

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 124721551 - 2²⁵ = 91167119 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 (124721501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134226 + ... + 135151.

It is an arithmetic number, because the mean of its divisors is an integer number (31247848).

Almost surely, 2^124721551 is an apocalyptic number.

124721551 is a deficient number, since it is larger than the sum of its proper divisors (269841).

124721551 is an equidigital number, since it uses as much as digits as its factorization.

124721551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269840.

The product of its digits is 2800, while the sum is 28.

The square root of 124721551 is about 11167.8803270809. The cubic root of 124721551 is about 499.6284586491.

Adding to 124721551 its reverse (155127421), we get a palindrome (279848972).

The spelling of 124721551 in words is "one hundred twenty-four million, seven hundred twenty-one thousand, five hundred fifty-one".