501661015 has 4 divisors (see below), whose sum is σ = 601993224. Its totient is φ = 401328808.

The previous prime is 501660997. The next prime is 501661019. The reversal of 501661015 is 510166105.

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 501661015 - 2¹⁵ = 501628247 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 (501661019) 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, 50166097 + ... + 50166106.

It is an arithmetic number, because the mean of its divisors is an integer number (150498306).

Almost surely, 2^501661015 is an apocalyptic number.

501661015 is a deficient number, since it is larger than the sum of its proper divisors (100332209).

501661015 is a wasteful number, since it uses less digits than its factorization.

501661015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100332208.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 501661015 is about 22397.7904044127. The cubic root of 501661015 is about 794.5784535195.

The spelling of 501661015 in words is "five hundred one million, six hundred sixty-one thousand, fifteen".