61986551 has 4 divisors (see below), whose sum is σ = 67621704. Its totient is φ = 56351400.

The previous prime is 61986523. The next prime is 61986571. The reversal of 61986551 is 15568916.

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

It is a cyclic number.

It is not a de Polignac number, because 61986551 - 2⁶ = 61986487 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61986499 and 61986508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61986511) 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, 2817560 + ... + 2817581.

It is an arithmetic number, because the mean of its divisors is an integer number (16905426).

Almost surely, 2^61986551 is an apocalyptic number.

61986551 is a deficient number, since it is larger than the sum of its proper divisors (5635153).

61986551 is a wasteful number, since it uses less digits than its factorization.

61986551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5635152.

The product of its digits is 64800, while the sum is 41.

The square root of 61986551 is about 7873.1538153398. The cubic root of 61986551 is about 395.7605407887.

It can be divided in two parts, 619865 and 51, that added together give a palindrome (619916).

The spelling of 61986551 in words is "sixty-one million, nine hundred eighty-six thousand, five hundred fifty-one".