61721427 has 8 divisors (see below), whose sum is σ = 83422864. Its totient is φ = 40583808.

The previous prime is 61721423. The next prime is 61721431. The reversal of 61721427 is 72412716.

It is an interprime number because it is at equal distance from previous prime (61721423) and next prime (61721431).

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

It is not a de Polignac number, because 61721427 - 2² = 61721423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61721394 and 61721403.

It is not an unprimeable number, because it can be changed into a prime (61721423) 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, 140698 + ... + 141135.

It is an arithmetic number, because the mean of its divisors is an integer number (10427858).

Almost surely, 2^61721427 is an apocalyptic number.

61721427 is a deficient number, since it is larger than the sum of its proper divisors (21701437).

61721427 is a wasteful number, since it uses less digits than its factorization.

61721427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281909.

The product of its digits is 4704, while the sum is 30.

The square root of 61721427 is about 7856.2985559359. The cubic root of 61721427 is about 395.1954958147.

The spelling of 61721427 in words is "sixty-one million, seven hundred twenty-one thousand, four hundred twenty-seven".