61408921 has 8 divisors (see below), whose sum is σ = 72601920. Its totient is φ = 50821008.

The previous prime is 61408891. The next prime is 61408943. The reversal of 61408921 is 12980416.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-61408921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61408021) 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, 151051 + ... + 151456.

It is an arithmetic number, because the mean of its divisors is an integer number (9075240).

Almost surely, 2^61408921 is an apocalyptic number.

It is an amenable number.

61408921 is a deficient number, since it is larger than the sum of its proper divisors (11192999).

61408921 is a wasteful number, since it uses less digits than its factorization.

61408921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302543.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 61408921 is about 7836.3844341635. The cubic root of 61408921 is about 394.5273864653.

The spelling of 61408921 in words is "sixty-one million, four hundred eight thousand, nine hundred twenty-one".