61651549 has 2 divisors, whose sum is σ = 61651550. Its totient is φ = 61651548.

The previous prime is 61651547. The next prime is 61651559. The reversal of 61651549 is 94515616.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60559524 + 1092025 = 7782^2 + 1045^2 .

It is a cyclic number.

It is not a de Polignac number, because 61651549 - 2¹ = 61651547 is a prime.

Together with 61651547, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61651543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30825774 + 30825775.

It is an arithmetic number, because the mean of its divisors is an integer number (30825775).

Almost surely, 2^61651549 is an apocalyptic number.

It is an amenable number.

61651549 is a deficient number, since it is larger than the sum of its proper divisors (1).

61651549 is an equidigital number, since it uses as much as digits as its factorization.

61651549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 37.

The square root of 61651549 is about 7851.8500367748. The cubic root of 61651549 is about 395.0462991181.

The spelling of 61651549 in words is "sixty-one million, six hundred fifty-one thousand, five hundred forty-nine".