61556421 has 8 divisors (see below), whose sum is σ = 84722944. Its totient is φ = 39713760.

The previous prime is 61556399. The next prime is 61556431. The reversal of 61556421 is 12465516.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61556421 - 2¹⁷ = 61425349 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 (61556431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 330856 + ... + 331041.

It is an arithmetic number, because the mean of its divisors is an integer number (10590368).

Almost surely, 2^61556421 is an apocalyptic number.

It is an amenable number.

61556421 is a deficient number, since it is larger than the sum of its proper divisors (23166523).

61556421 is a wasteful number, since it uses less digits than its factorization.

61556421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661931.

The product of its digits is 7200, while the sum is 30.

The square root of 61556421 is about 7845.7900175827. The cubic root of 61556421 is about 394.8430097707.

The spelling of 61556421 in words is "sixty-one million, five hundred fifty-six thousand, four hundred twenty-one".