61501621 has 4 divisors (see below), whose sum is σ = 61519500. Its totient is φ = 61483744.

The previous prime is 61501619. The next prime is 61501633. The reversal of 61501621 is 12610516.

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 60996100 + 505521 = 7810^2 + 711^2 .

It is a cyclic number.

It is not a de Polignac number, because 61501621 - 2¹ = 61501619 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61501592 and 61501601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61505621) 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, 1966 + ... + 11263.

It is an arithmetic number, because the mean of its divisors is an integer number (15379875).

Almost surely, 2^61501621 is an apocalyptic number.

It is an amenable number.

61501621 is a deficient number, since it is larger than the sum of its proper divisors (17879).

61501621 is a wasteful number, since it uses less digits than its factorization.

61501621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17878.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 61501621 is about 7842.2969211832. The cubic root of 61501621 is about 394.7258066120.

The spelling of 61501621 in words is "sixty-one million, five hundred one thousand, six hundred twenty-one".