61620521 has 4 divisors (see below), whose sum is σ = 61645200. Its totient is φ = 61595844.

The previous prime is 61620497. The next prime is 61620539. The reversal of 61620521 is 12502616.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61620521 is a prime.

It is a super-2 number, since 2×61620521² = 7594177216622882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61625521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8111 + ... + 13748.

It is an arithmetic number, because the mean of its divisors is an integer number (15411300).

Almost surely, 2^61620521 is an apocalyptic number.

It is an amenable number.

61620521 is a deficient number, since it is larger than the sum of its proper divisors (24679).

61620521 is a wasteful number, since it uses less digits than its factorization.

61620521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24678.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 61620521 is about 7849.8739480325. The cubic root of 61620521 is about 394.9800150120.

The spelling of 61620521 in words is "sixty-one million, six hundred twenty thousand, five hundred twenty-one".