61421531 has 4 divisors (see below), whose sum is σ = 61995672. Its totient is φ = 60847392.

The previous prime is 61421453. The next prime is 61421573. The reversal of 61421531 is 13512416.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61421531 is a prime.

It is a super-2 number, since 2×61421531² = 7545208940767922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61421497 and 61421506.

It is not an unprimeable number, because it can be changed into a prime (60421531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286910 + ... + 287123.

It is an arithmetic number, because the mean of its divisors is an integer number (15498918).

Almost surely, 2^61421531 is an apocalyptic number.

61421531 is a deficient number, since it is larger than the sum of its proper divisors (574141).

61421531 is a wasteful number, since it uses less digits than its factorization.

61421531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574140.

The product of its digits is 720, while the sum is 23.

The square root of 61421531 is about 7837.1889730949. The cubic root of 61421531 is about 394.5543893273.

Adding to 61421531 its reverse (13512416), we get a palindrome (74933947).

The spelling of 61421531 in words is "sixty-one million, four hundred twenty-one thousand, five hundred thirty-one".