61213621 has 16 divisors (see below), whose sum is σ = 71884800. Its totient is φ = 51043248.

The previous prime is 61213571. The next prime is 61213627. The reversal of 61213621 is 12631216.

It is a cyclic number.

It is not a de Polignac number, because 61213621 - 2²¹ = 59116469 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61213592 and 61213601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61213627) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41820 + ... + 43258.

It is an arithmetic number, because the mean of its divisors is an integer number (4492800).

Almost surely, 2^61213621 is an apocalyptic number.

It is an amenable number.

61213621 is a deficient number, since it is larger than the sum of its proper divisors (10671179).

61213621 is a wasteful number, since it uses less digits than its factorization.

61213621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1608.

The product of its digits is 432, while the sum is 22.

The square root of 61213621 is about 7823.9134069850. The cubic root of 61213621 is about 394.1087012296.

Adding to 61213621 its reverse (12631216), we get a palindrome (73844837).

The spelling of 61213621 in words is "sixty-one million, two hundred thirteen thousand, six hundred twenty-one".