61662521 has 4 divisors (see below), whose sum is σ = 62673444. Its totient is φ = 60651600.

The previous prime is 61662487. The next prime is 61662529. The reversal of 61662521 is 12526616.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12816400 + 48846121 = 3580^2 + 6989^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61662521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61662529) 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, 505370 + ... + 505491.

It is an arithmetic number, because the mean of its divisors is an integer number (15668361).

Almost surely, 2^61662521 is an apocalyptic number.

61662521 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

61662521 is a deficient number, since it is larger than the sum of its proper divisors (1010923).

61662521 is a wasteful number, since it uses less digits than its factorization.

61662521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010922.

The product of its digits is 4320, while the sum is 29.

The square root of 61662521 is about 7852.5486945322. The cubic root of 61662521 is about 395.0697329218.

The spelling of 61662521 in words is "sixty-one million, six hundred sixty-two thousand, five hundred twenty-one".