1651512551 has 4 divisors (see below), whose sum is σ = 1778551992. Its totient is φ = 1524473112.

The previous prime is 1651512529. The next prime is 1651512553. The reversal of 1651512551 is 1552151561.

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 1651512551 - 2⁶ = 1651512487 is a prime.

It is a super-2 number, since 2×1651512551² = 5454987412221055202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1651512553) 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, 63519701 + ... + 63519726.

It is an arithmetic number, because the mean of its divisors is an integer number (444637998).

Almost surely, 2^1651512551 is an apocalyptic number.

1651512551 is a deficient number, since it is larger than the sum of its proper divisors (127039441).

1651512551 is a wasteful number, since it uses less digits than its factorization.

1651512551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127039440.

The product of its digits is 7500, while the sum is 32.

The square root of 1651512551 is about 40638.8059740933. The cubic root of 1651512551 is about 1182.0267169005.

The spelling of 1651512551 in words is "one billion, six hundred fifty-one million, five hundred twelve thousand, five hundred fifty-one".