6721501157 has 24 divisors (see below), whose sum is σ = 8311301784. Its totient is φ = 5401116672.

The previous prime is 6721501133. The next prime is 6721501229. The reversal of 6721501157 is 7511051276.

It can be written as a sum of positive squares in 4 ways, for example, as 3677330881 + 3044170276 = 60641^2 + 55174^2 .

It is not a de Polignac number, because 6721501157 - 2¹⁰ = 6721500133 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 (6721504157) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198383 + ... + 229779.

It is an arithmetic number, because the mean of its divisors is an integer number (346304241).

Almost surely, 2^6721501157 is an apocalyptic number.

It is an amenable number.

6721501157 is a deficient number, since it is larger than the sum of its proper divisors (1589800627).

6721501157 is a wasteful number, since it uses less digits than its factorization.

6721501157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31685 (or 31678 counting only the distinct ones).

The product of its (nonzero) digits is 14700, while the sum is 35.

The square root of 6721501157 is about 81984.7617365569. The cubic root of 6721501157 is about 1887.2180975248.

The spelling of 6721501157 in words is "six billion, seven hundred twenty-one million, five hundred one thousand, one hundred fifty-seven".