61621621 has 4 divisors (see below), whose sum is σ = 62197632. Its totient is φ = 61045612.

The previous prime is 61621603. The next prime is 61621627. The reversal of 61621621 is 12612616.

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 not a de Polignac number, because 61621621 - 2⁵ = 61621589 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 (61621627) 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, 287845 + ... + 288058.

It is an arithmetic number, because the mean of its divisors is an integer number (15549408).

Almost surely, 2^61621621 is an apocalyptic number.

It is an amenable number.

61621621 is a deficient number, since it is larger than the sum of its proper divisors (576011).

61621621 is a wasteful number, since it uses less digits than its factorization.

61621621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576010.

The product of its digits is 864, while the sum is 25.

The square root of 61621621 is about 7849.9440125392. The cubic root of 61621621 is about 394.9823652865.

The spelling of 61621621 in words is "sixty-one million, six hundred twenty-one thousand, six hundred twenty-one".