61542251 has 4 divisors (see below), whose sum is σ = 62585400. Its totient is φ = 60499104.

The previous prime is 61542241. The next prime is 61542253. The reversal of 61542251 is 15224516.

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-61542251 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61542251.

It is not an unprimeable number, because it can be changed into a prime (61542253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 521486 + ... + 521603.

It is an arithmetic number, because the mean of its divisors is an integer number (15646350).

Almost surely, 2^61542251 is an apocalyptic number.

61542251 is a deficient number, since it is larger than the sum of its proper divisors (1043149).

61542251 is a wasteful number, since it uses less digits than its factorization.

61542251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043148.

The product of its digits is 2400, while the sum is 26.

The square root of 61542251 is about 7844.8869335383. The cubic root of 61542251 is about 394.8127104414.

Adding to 61542251 its reverse (15224516), we get a palindrome (76766767).

The spelling of 61542251 in words is "sixty-one million, five hundred forty-two thousand, two hundred fifty-one".