61554431 has 2 divisors, whose sum is σ = 61554432. Its totient is φ = 61554430.

The previous prime is 61554419. The next prime is 61554497. The reversal of 61554431 is 13445516.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61554431 is a prime.

It is a super-2 number, since 2×61554431² = 7577895951467522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 61554394 and 61554403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61554401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30777215 + 30777216.

It is an arithmetic number, because the mean of its divisors is an integer number (30777216).

Almost surely, 2^61554431 is an apocalyptic number.

61554431 is a deficient number, since it is larger than the sum of its proper divisors (1).

61554431 is an equidigital number, since it uses as much as digits as its factorization.

61554431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7200, while the sum is 29.

The square root of 61554431 is about 7845.6631969515. The cubic root of 61554431 is about 394.8387548880.

Adding to 61554431 its reverse (13445516), we get a palindrome (74999947).

It can be divided in two parts, 6155 and 4431, that multiplied together give a triangular number (27272805 = T₇₃₈₅).

The spelling of 61554431 in words is "sixty-one million, five hundred fifty-four thousand, four hundred thirty-one".